From Dummy to Computing friendly

6 tips for your Google+

noreply@blogger.com (Unknown) — Sat, 24 Mar 2012 14:51:00 +0000

Google has finally found a way out by rolling to their dedicated Google community with a highly competent social networking site to the current biggies like ‘Facebook and Twitter’. This community that they intend to develop has been named Google+.

Some of the tips for using Google+ will include:

1. Rotate your profile pictures:
Click on the profile pictures to rotate them, this makes life much easier and this is an option that is not available in none of the other social networking sites. Facebook being the most popular photo-sharing site has this option of rotating the photos only when you open the individual photos in the photo album, but not in profile photo space itself. This is an added advantage, and is a very interesting and useful feature in Google+.

2. Format your text:
Follow these simple tricks while formatting your text in Google + status update column, which is not available in other social networking websites. Yet another interesting feature! Do the following to format your text!
• (*) bold (*) – add star before and after the message to bold the font.
• (_) italics (_) – add _ (underscore) before and after the message to italicize the font the text.
• (-) strike through (-) – add – (dash) before and after the message to strike through the text.

3. Specify your post to someone:
You can specifically mention someone in your post. This is a common practice and is a “post manners” amongst social networking community. All you need to do is to add a + or @ signal before the beginning of the post to mention specifically someone.

4. Timestamp:
When you are in need of getting a permalink or the web URL of a specific link that has been shared on the Google+ all you need to do is to click on the timestamp tool and there you will have the web URL right in front of you. This is the similar to how you will be getting the web URL in other social networking websites also.

5. Control who sees your post:
The decision of who sees your post is in your hands in Google +. This is possible to share your post with Public or Circle or Circles only, that you can share a post even with a particular individual by typing their name or email address. In Facebook and twitter, you type only names!

6. Edit photos in Google+:
Coming from Google, Google+ is powered with the ability to edit your photos and do more than merely cropping your photos that you are allowed to do in most of your social networking websites. How you go about editing photos in Google+ is by opening the uploaded picture from the photo gallery, and choose the action to edit photos, which opens up many avenues of editing your photos that you can exploit.

These are some of the tips from the extensive list of tips for Google+

ArmStrong Number

noreply@blogger.com (Unknown) — Fri, 16 Mar 2012 03:17:00 +0000

An Armstrong number of three digits is an integer such that the sum of the cubes of its digits is equal to the number itself. For example, 371 is an Armstrong number since 3**3 + 7**3 + 1**3 = 371.

Write a program to find all Armstrong number in the range of 0 and 999.

#include<stdio.h>
#include<conio.h>
 
main()
{
   int number, sum = 0, temp, remainder;
 
   printf("Enter a number\n");      
   scanf("%d",&number);
 
   temp = number;
 
   while( temp != 0 )
   {
      remainder = temp%10;
      sum = sum + remainder*remainder*remainder;
      temp = temp/10; 
   }
 
   if ( number == sum )
      printf("Entered number is an armstrong number.");
   else
      printf("Entered number is not an armstrong number.");         
 
   getch();
   return 0;
}

Output:

Further Reading....
http://www.programmingsimplified.com/c-program-find-armstrong-number

Reading Comprehension 1 Answers

noreply@blogger.com (black parody) — Wed, 14 Mar 2012 07:52:00 +0000

Here are the answers of this week's reading comprehension questions. To check the questions, click here.
In case of any doubts, feel free to contact me at nardz07@gmail.com

1. c. To be outmoded is to be old-fashioned or out-of date. The designer window treatments may also be unnecessary, pointless, or even worthless.
However, the key to the meaning is the context — that is, the phrase installed 17 years ago.

2. c. Something that is wearisome is tiresome or boring. The key to the meaning here is the
phrase they regularly put students to sleep.

3. a. To be spiteful is to be vengeful or vindictive. The keys here are the word malice and the
phrase almost ruined the referee’s career.

4. d. When something is done obdurately, it is done in an inflexible or intractable manner,
or stubbornly. The key here are the words willful young man.

5. b. A superficial remark is insignificant and shallow, or petty. The key here is the word
trivialized.

6. a. To be ostracized is to be banished or excluded. The key here is the phrase usually loyal
friends, who had never shunned her before.

7. b. Something that is flamboyant is flashy or showy. The keys here are the words usually
described as flamboyant and but…uncharacteristically modest.

8. b. To be gullible means to be easy to fool or naïve. The keys here are the words outlandish
excuses and insincere employees.

9. a. A prerequisite is something that is necessary or required. The fact that you can’t become a
certified teacher without completing the student teaching assignment means that it is
required. The other choices do not imply a hard and fast rule.

10. c. To be diligent is to be painstaking or thorough.

Linux Commands

noreply@blogger.com (Anonymous) — Tue, 13 Mar 2012 01:01:00 +0000

Here is a list of basic linux commands. This list of linux commands is not complete as there are many more linux commands available. However, it should make a good start for a beginner or intermediate linux administrator / linux user.

§ alias - create names or abbreviations for commands

§ apropos - search the manual page names and descriptions

§ at [man page] - queue, examine or delete jobs for later execution

§ bc [man page] - An arbitrary precision calculator language

§ cal - displays a calendar

§ cat [man page] - concatenate files and print on the standard output

§ cd - change directory

§ chgrp [man page] - change group ownership

§ chmod [man page] - change file access permissions

§ cksum [man page] - checksum and count the bytes in a file

§ cp [man page] - copy files and directories

§ csplit [man page] - split a file into sections determined by context lines

§ date [man page] - print or set the system date and time

§ dd [man page] - convert and copy a file

§ du [man page] - estimate file space usage

§ egrep [man page] - print lines matching a pattern

§ export - set an environment variable

§ fgrep [man page] - print lines matching a pattern

§ find [man page] - search for files in a directory hierarchy

§ fold [man page] - wrap each input line to fit in specified width

§ grep [man page] - print lines matching a pattern

§ head [man page] - output the first part of files

§ join [man page] - join lines of two files on a common field

§ logrotate [man page] - rotates, compresses, and mails system logs

§ ls [man page] - list directory contents

§ mkdir [man page] - make directories

§ mv [man page] - move (rename) files

§ mount [man page] - mount a file system

§ nl [man page] - number lines of files

§ od [man page] - dump files in octal and other formats

§ pwd [man page] - print name of current/working directory

§ rgrep [man page] - print lines matching a pattern

§ rm [man page] - remove files or directories

§ scp - secure copy (remote file copy program)

§ ssh - OpenSSH SSH client (remote login program)

§ tail [man page] - output the last part of files

§ tar [man page] - The GNU version of the tar archiving utility

§ tee [man page] - read from standard input and write to standard output and files

§ time [man page] - run programs and summarize system resource usage

§ touch [man page] - change file timestamps

§ vim - Vi IMproved, a programmers text editor

§ watch [man page] - execute a program periodically, showing output fullscreen

§ wc [man page] - print newline, word, and byte counts for each file

§ whoami [man page] - print effective userid

· yes [man page] - output a string repeatedly until killed

A few Gate Books For CSE Students

noreply@blogger.com (black parody) — Mon, 12 Mar 2012 21:25:00 +0000

Preparing for the Computer Science paper of the GATE? Here is all the material that we, at DummyLearns scraped through the internet, and uploaded, just for you.

Our package for you is divided into three parts:

1. The GATE Preparation books
2. The GATE oriented PPTs
3. The previous year GATE papers

Note: Wait for 5 seconds on adf.ly, and when the skip ad pic appears, either

1. Drag the icon to the address bar, or
2. Right click > Copy link location > Paste in address bar.

To check out the various books we have lined up for you, click here.

The individual books uploaded so far include:

1. DBMS, By Ullman
2. Galvin 6th Edition, Solution
3. Graph Theory
4. Introduction To Algorithms
5. Introduction to Theory of Computation
6. OS, William Stallings
7. Algorithms and Data Structures, Nikhlaus Wirth
8. Introduction to Formal Language Automata
9. Embedded Systems, Raj Kamal
10. Computer Systems Architecture, WIlliams
11. CMOS VLSI Design, Weste
12. Discrete Math Notes
13. Calculus
14. Data Structures and Algorithm Analysis, Weiss
15. Digital Logic and Computer Design
16. Compiler Design, Aho, Sethi
17. Fundamentals Of Computer Architecture
18. Java2, A complete Reference
19. DBMS, Korth, Solutions

And more to follow...

The Gate preparation CD gives a few lecture PPTs which you can browse here.

Or you can individually download each one here based on the topic you need:

0. Outline
1. Lexical Analyser
2. CFG Parser
3. Updown Parser
4. Bottomup parser
5. Syntax Directed
6. Type Checked
7. Intermediate CG
8. Memory Organisation

We have added quite a repository of previous years' question papers for you. To browse, navigate here.

Or to download based on year:

1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011

These posts will be updated regularly, and if you want material for anything specific, please ask in the comments section, or write to any of the authors. Also, please contribute whatever material you might have so it may benefit us all.

Thanks, adieu!

Automatic Replies in Gmail

noreply@blogger.com (black parody) — Sun, 11 Mar 2012 20:31:00 +0000

So here I was, applying for some internship posts via email, when I got replies from each of them within seconds informing me that they are not in Office, and would attend to my messages as sson as they found the time for it. This intrigued me in the following respects, which I have discussed in detail below:

1. Is it possible to set automatic replies for certain durations (vacations)
2. Is it possible to set automatic reply to certain senders, or for certain purposes

1. Vacation responder

Gmail > Settings > General > Vacation Responder

The activation of this facility allows the account to set a period (date 1 to date 2) wherein any mail received will receive a reply instantaneously stating whatever you have recorded beforehand.

Now, if we wanted to send automatic mails to only certain email ids... In such a scenario,

2. Canned Response

Go to Settings > Labs

Search Canned Responses and enable

Now go to compose mail, and type in the message you want to send by default. Save it under any name so you can remember which message to send:

This allows you to simply choose the canned message you send each time instead of having to type out the entire mail over and over again.

Now, go to Settings > Filters

Click Create new filter.

You can create a filter based on the subject, in which case all mails with said subject or having the specified word/phrase as part of its subject will be included.

Or, specific keywords can be given for the same purposes

Filters can be added with recipient or target addresses also.

Once a filter has been searched,

Choose the canned response you want to give for each of these mails, and save. Now whenever the conditions of any of the filters created are fulfilled, the desired canned response will be sent to the sender.

Thats all for now, enjoy!

Reading Comprehension Part 1

noreply@blogger.com (black parody) — Sat, 10 Mar 2012 21:53:00 +0000

Read the following sentences and try to choose the best definition for the italicized word by searching for context clues in the sentence. Answers coming next post...

1. The designer window treatments in her house, installed 17 years ago, were outmoded.

a. unnecessary
b. pointless
c. out-of-date
d. worthless

2. Although the professor’s lectures were regarded by many as so wearisome that they regularly put
students to sleep, he ignored all criticism and refused to make any changes.

a. modest
b. unpleasant
c. boring
d. objectionable

3. The baseball player’s malice toward the referee was revealed in his spiteful remarks to the media,
which almost ruined the referee’s career.

a. vindictive
b. crazy
c. rude
d. unpleasant

4. Although Zachary is much too inexperienced for the managerial position, he is a willful
young man and obdurately refuses to withdraw his application.

a. foolishly
b. reluctantly
c. constantly
d. stubbornly

5. His neighbor’s superficial remarks trivialized the property line dispute and infuriated Malcolm.

a. enraged
b. petty
c. insulting
d. misleading

6. When Katya refused to lie to her parents about where she was spending the night, she was completely ostracized by her usually loyal friends, who had never shunned her before.

a. excluded
b. hurt
c. cheered
d. helped

7. Her fashion sense was usually described as flamboyant, but on the night of the party, Tanya’s outfit
was uncharacteristically modest.

a. impeccable
b. showy
c. sloppy
d. unassuming

8. Mr. Powers was so gullible that he believed even the most outlandish excuses of his insincere
employees.

a. intelligent
b. naïve
c. dishonest
d. critical

9. You cannot become a certified teacher without completing the prerequisite student teaching
assignment.

a. required
b. optional
c. preferred
d. advisable

10. Charles, aware of his susceptibility to gum disease, is diligent about flossing.

a. uncomfortable
b. excited
c. thorough
d. ambivalent

Ungala Yaarum Ketkala - Trailer

noreply@blogger.com (Anonymous) — Sat, 21 Jan 2012 06:55:00 +0000

The blackout against SOPA and PIPA

noreply@blogger.com (black parody) — Thu, 19 Jan 2012 02:30:00 +0000

18th Jan 2012 - Blackout Day

This new year, the US legislature brought two acts to be added into the law books - The STOP ONLINE PIRACY ACT (SOPA) and The PROTECT IP ACT (PIPA). However these acts met with mighty opposition from internet users all around the world, with giants like

Wikipedia, Craigslist, Boing Boing, A Softer World, Cake Wrecks, Cyanide and Happiness, Destructoid, DeckTech.net, Free Press, Failblog, Newgrounds, Good.is, Good Old Games, Gamesradar, Internet Archive, Jay is Games, Mojang,MoveOn.org, Mozilla, MS Paint Adventures, Rate Your Music, Oh No They Didn't, Tucows, What Dat.net, ThatGuyWithTheGlasses, Tumblr, TwitPic, VGMusic, Wikia, Wordpress, xkcd, Galobuzz as well as the corporate site of the Linux distribution openSUSE and the congressional websites of Silicon Valley representatives Anna Eshoo and Zoe Lofgren, and 115,000 other websites blacked themselves out for the day. Google did not black itself out, but did put a link out on its main search engine informing everyone about SOPA and the PIPA and their stand against it, with the reasons behind it.

This website also blacked itself out for a day, even though we are not based in the US. This is because, most countries have cyber laws, tat echo those in the USA. With Mr Kapil Sibal already making his moves against privacy and the unrestricted usage in India in general, it would not be a long leap, before these laws hit us, For many, who do not understand how these acts were not apt, and caused more damage than help, can check out http://en.wikipedia.org/wiki/Wikipedia:SOPA_initiative for why Wikipedia went after it, http://en.wikipedia.org/wiki/2012_Wikipedia_blackout#Wikimedia_community.

http://www.pcworld.com/article/248298/sopa_and_pipa_just_the_facts.html

http://www.lionsroarnews.com/opinions/stand-against-sopa-and-pipa-1.2749208#.Tx9r2hL9OcQ

http://www.1stwebdesigner.com/design/how-sopa-pipa-can-affect-you/

Hope we could reach out to you, and you can reach out to others to help us stop these laws.

Tweaking Linux To meet User Needs

noreply@blogger.com (black parody) — Tue, 15 Nov 2011 15:06:00 +0000

Till recently I was using Fedora 15 - "Lovelock" as my alternate OS, which usually is always a Linux flavor. Now, at present I am using Ubuntu 11.10 - "Oneiric Ocelot" on my system. One thing one must realize, is that Linux distributions run in a very different manner from Windows. They do not (yet) support executable facility, so the installation of many a software is not as easy or automatic as in windows. Also, a general OS install of Linux distributions is very general. It does not do much more than install the kernel and other must haves in order to run a system. They do, however provide repositories for the easy installation of many open source softwares that are popular, or open source alternatives to commercial softwares.

Fedora 15:

Ubuntu 11.10:

In this post, I will entail the different softwares that I feel one MUST have in their system, and how to go about installing them - in fedora 15 and in ubuntu 11.10. Please note, that this is simply a comparitive study.

First and foremost, it is necessary to update whatever repositories the installation disk gives you or to add requisite repositories before you start.

In Fedora,

simply type in the terminal

su - yum update

Note: We use su - to authorise ourselves as root. In ubuntu, the admin user himself can act as root, but in fedora, root is separate from home, and hence, whenever we make any system changes we need to declare our root password.

Also, most probably, in laptops, your wifi driver will not be auto installed. For this, follow my post on wifi activation in fedora.

In Ubuntu 11.10,

simply type in the terminal

sudo apt-get update

followed by

sudo apt-get upgrade

to update and upgrade the repositories from time to time.

Note: We use sudo to express that the user requesting the changes themselves has root authority.

Ubuntu, by default does not activate all additional drivers that are system specific at install time, like the broadcom driver. To install them,

Open additional drivers as shown in the unity dash page screenshot above. Select the driver you want to activate from all the ones the OS can detect on your system, and click activate. This should do the trick.

---------------------------------------

By default Linux does not have the support to play all the mp3 and other common media files that windows can. to install these plugins,

In fedora, type

su - yum -y install gstreamer-plugins-bad gstreamer-plugins-ugly xine-lib-extras-nonfree gstreamer-ffmpeg

yum install ffmpeg ffmpeg-libs

yum install libdvdread libdvdnav lsdvd

To install flash,

Visit http://get.adobe.com/flashplayer/ and select YUM for Linux from the drop down box.

This will download the file named adobe-release-i386-1.0-1.noarch.rpm.

Open a terminal and issue the following command within the directory where you have downloaded the repository rpm file.

su -c 'rpm -ivh adobe-release-i386-1.0-1.noarch.rpm'

The .rpm file also copies the adobe General Public Key (GPG key) to /etc/pki/rpm-gpg/RPM-GPG-KEY-adobe-linux but does not import it.

To import the key, do the following…

su -c 'rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-adobe-linux'

In the terminal, execute the following command …

su -c 'yum install nspluginwrapper alsa-plugins-pulseaudio flash-plugin'

Now fedora will update the repository databases and then download the Adobe flash plugin from the adobe website.

It is a 5.2 MB download.

In ubuntu, type on the terminal

sudo apt-get install ubuntu-restricted-extras

This will activate all media plugins and flash software.

------------------------------------------

VLC media player is the most popular software to play media files in linux because it can read almost every codec or plugin possible.

In Fedora, to install vlc simply type

yum install vlc

as root.

In Ubuntu.

sudo apt-get install vlc

-------------------------------------------

Filezilla is the best ftp software available in open source technologies. To install filezilla

Fedora: yum install filezilla

Ubuntu: sudo apt-get install filezilla

-------------------------------------------

Photo editing and Image manipulation is very easy with the GNU Image Manipulation Program, or GIMP

Ubuntu: sudo apt-get install gimp

Fedora: su - yum install gimp

---------------------------------------------

We all are programmers, and will use opensource LAMP technologies sooner or later. Here is a how-to to install the xampp package on linux.

Firstly, one must know what all xampp provides you. It gives you an apache server, mysql and php packages. Also, it gives you a PERL structure. Now, its easier to install xampp and be done with it, or you could install each software separately.

For example, in Fedora,

PHP: yum install php-xml

PHP with Apache: yum install httpd php php-common

Mysql: yum install mysql-workbench

Instead if you want to install the xampp package for linux, found here, then its only two easy steps:

1. Download the most recent version of XAMPP

2. Extract the archive to /opt using sudo: (make sure you are in the directory that you downloaded the archive to)

sudo tar xvfz xampp-linux-1.5.3a.tar.gz -C /opt

Now whenever you want to use any of the xampp packages simply open your terminal and type

sudo /opt/lampp/lampp start

And to stop it,

sudo /opt/lampp/lampp stop

The steps are same for ubuntu and fedora, only fedora will have su - instead of sudo.

-----------------------------------------------

Qt is a cross platform framework IDE developed under Nokia's banner. To know more about it, see this.

In Ubuntu 11.10, qt is already added and installed, so just open your Unity Dash, and search Qt:

In Fedora 15, you can simply install the Qt toolkit by typing

yum install qt-devel qt-config

31 Useful Ubuntu 11.10 Unity Keyboard/Mouse Shortcuts

noreply@blogger.com (black parody) — Thu, 10 Nov 2011 04:06:00 +0000

In my opinion, the overall Ubuntu 11.04 / 11.10 experience is so much better and involving if you know some essential Ubuntu Unity keyboard and Mouse shortcuts. So here are a bunch of very basic yet useful Ubuntu 11.04 / 11.10 (Unity) keyboard shortcuts. Thanks to askubuntu for the list.

Ubuntu Unity Shortcuts

Super Key(Windows Key) - Opens dash.

Hold Super Key - Invokes Launcher.

Hold Super Key and hit 1, 2, 3 etc - Open an Application from Launcher. When you hold the Super Key, specific numbers will be displayed in order above each application.

Alt + F1 - Put keyboard focus on the Launcher, use arrow keys to navigate, Enter launches the application, Right arrow exposes the quicklists if an application has them.

Alt + F2 - Opens dash in special mode to run any commands.

Super + A - Opens up application window from launcher.

Super + F - Opens up files and folders window from launcher. Both these shortcuts can be viewed by simply holding the Super Key as well.

Super + W - Spread mode, zoom out on all windows in all workspaces.

Super + D - Minimize all windows(acts as Show Desktop). Hitting it again restores them.

Super + T - Opens trash can.

Super + S - Expo mode (for everything), zooms out on all the workspaces and let's you manage windows.

Ctrl + Alt + T - Launch Terminal.

Ctrl + Alt + L - Lock Screen.

Ctrl + Alt + Left/Right/Up/Down - Move to new workspace.

Ctrl + Alt + Shift + Left/Right/Up/Down - Place window to a new workspace.

F10 - Open the first menu on top panel, use arrows keys to browse across the menus.

Mouse Shortcuts/Tricks for Ubuntu Unity

Clicking and holding an icon and then dragging it around will allow you to reorder it on the launcher. You can also drag it off to the right of the launcher to move it around. Note that you need to make an explicit movement to the right to move the icon off the launcher before you can move it around.

Dragging and Dropping an icon into the trash can will remove it from the Launcher.

Moving and holding the cursor on the left side for a few seconds will launch Unity dock.

Moving the cursor to top-left corner(near Ubuntu icon) will launch Unity dock as well.

Scrolling the mouse wheel while over the Launcher scrolls the icons if you have too many and need to move around quickly.

By Scrolling the mouse wheel while over the Sound icon on top panel helps you increase or decrease system volume.

Middle click on an application's launcher icon - Open a new instance of the application in a new window. Very useful at times. In laptops with touchpads, hitting left/right click buttons together is akin to middle click.

Maximizing - Dragging a window to the top panel will maximize it.

Restore/Unmaximize - Dragging the top panel down OR double clicking on the top panel will do.

Tiling - Dragging a Window to the left/right border will auto tile it to that side of the screen. One of the highlights of new Unity experience.

And Some Useful Window Management Shortcuts(Generic)

Alt + F10 - Toggle between Maximize/Unmaximize current window.

Alt + F9 - Minimize current window.

Alt + Tab - Toggle between currently open windows.

Alt + F4 - Closes current window.

Alt + F7 - Moves the current window(both keyboard and mouse can be used).

Aptitude Answers 3

noreply@blogger.com (Anonymous) — Fri, 04 Nov 2011 13:43:00 +0000

Here are the answers to the last week's aptitude questions. Read more for the answers. Refer here for the corresponding questions!!!

1.Answer 65292

As per given conditions, there are three possible combinations for 2nd, 3rd and 4th digits. They are (3, 0, 7) or (4, 1, 8) or (5, 2, 9) It is given that there are 3 pairs whose sum is 11. All possible pairs are (2, 9), (3, 8), (4, 7), (5, 6). Now required number is 5 digit number and it contains 3 pairs of 11. So it must not be having 0 and 1 in it. Hence, the only possible combination for 2nd, 3rd and 4th digits is (5, 2, 9) Also, 1st digit is thrice the last digit. The possible combinations are (3, 1), (6, 2) and (9, 3), out of which only (6, 2) with (5, 2, 9) gives 3 pairs of 11. Hence, the answer is 65292.

2.Answer:

The next letters in the series are N, O, R, S, U, X. The pattern is - letters whose English names (Phonetic Pronunciations) start with vowels.

3.Answer:

This is a series with odd positions containing position number whereas even positions containing square of the position.i.e. even position numbers are 4 16 36 64 100 and odd position numbers are 1 3 5 7 9 Hence, 6 does not fit in the series. It should be 5.

4.Answer:

The mother is 29 years and 2 months old. Let's assume that son is X years old. Hence, father is 6X years old and mother is (70-7X) years old. It is given that the sum of their ages is 70, which will total 140 after 70/3 years. After 70/3 years, son will be (X + 70/3) years old and father will be (6X + 70/3) years old. Also, it is given that after 70/3 years, the father will be twice as old as the son. Thus, (6X + 70/3) = 2 * (X + 70/3) 6X + 70/3 = 2X + 140/3 4X = 70/3 X = 35/6 Hence, their ages are Son = X = 35/6 = 5 years and 10 months Father = 6X = 6(35/6) = 35 years Mother = (70 - 7X) = 70 - 7(35/6) = 29 years and 2 months

5.Answer:

We tried to find out some simple mathematical method and finally we wrote small C program to find out the answer. The answer is 3121 coins. Here is the breakup: First son = 624 coins Second son = 499 coins Third son = 399 coins Forth son = 319 coins Fifth son = 255 coins Daughters = 204 each Manager = 5 coins

6. Answer

1. Mark the boxes with numbers 1, 2, 3, 4, ... upto 10 2. Take 1 ball from box 1, take 2 balls from box 2, take 3 balls from box 3, take 4 balls from box 4 and so on 3. Put all of them on the scale at once and take the measurement. 4. Now, subtract the measurement from 550 ( 1*10 + 2*10 + 3*10 + 4*10 + 5*10 + 6*10 + 7*10 + 8*10 + 9*10 + 10*10) 5. The result will give you the box number which has a ball of 9 Kg

7.Answer:

224

8. Answer:

For next number add one = 3

Next add one = 7 and so on ...

Now at 31, for next number double the number = 62

Add one for next number = 63

Answer

Next two numbers are 62 and 63.

The pattern is double the number, add one, double the number, add one...

Starting with 1, for next number double the number = 2 Again, double the number = 6

9.Answer

The minute and the hour hand meet 11 times in 12 hours in normal watch i.e. they meet after every

= (12 * 60) / 11 minutes

= 65.45 minutes

= 65 minutes 27.16 seconds

But in our case they meet after every 65 minutes means the watch is gaining 27.16 seconds.

10.Answer

There are total of 64 blocks on a chessboard. So 3 blocks can be chosen out of 64 in 64C3 ways.

So the sample space is = 41664

There are 2 diagonal on chessboard each one having 8 blocks. Consider one of them.

3 blocks out of 8 blocks in diagonal can be chosen in 8C3 ways.

But there are 2 such diagonals, hence favourables = 2 * 8C3 = 2 * 56 = 112

The require probability is

= 112 / 41664

= 1 / 372

= 0.002688

QT - An introduction

noreply@blogger.com (black parody) — Wed, 02 Nov 2011 06:17:00 +0000

Qt is a cross-platform application framework that is widely used for developing application software with a graphical user interface (GUI) (in which cases Qt is classified as a widget toolkit), and also used for developing non-GUI programs such as command-line tools and consoles for servers. It is produced by Nokia.

Qt is most notably used in Autodesk Maya, Adobe Photoshop Elements, OPIE, Skype, VLC media player, VirtualBox, and Mathematica, and by the European Space Agency, DreamWorks, Google, HP, KDE, Lucasfilm, Panasonic, Philips, Samsung, Siemens, Volvo, and Walt Disney Animation Studios.

It is currently produced by Nokia's Qt Development Frameworks division, which came into being after Nokia's acquisition of the Norwegian company Trolltech, the original producer of Qt. Nokia announced that it is going to drop Symbian technologies and base their future smartphones on Microsoft platform instead in February 2011. One month later Nokia announced the sale of Qt's commercial licensing and professional services to Digia PLC, although Nokia will remain the main development force behind the framework. Qt5 is expected to release in early 2012.

Qt is officially pronounced as cute, but unofficially, and due to its shadowing by stronger market giants like microsoft, it is still pronounced as Q T.

Qt uses standard C++ but makes extensive use of a special code generator (called the Meta Object Compiler, or moc) together with several macros to enrich the language. Qt can also be used in several other programming languages via language bindings. It runs on the major desktop platforms and some of the mobile platforms. It has extensive internationalization support. Non-GUI features include SQL database access, XML parsing, thread management, network support, and a unified cross-platform API for file handling.

Distributed under the terms of the GNU Lesser General Public License (among others), Qt is free and open source software. All editions support a wide range of compilers, including the GCC C++ compiler and the Visual Studio suite.

Windows may not have Qt and may need to be downloaded from here. Most Linux distributions include Qt in their repositories, but they can also be downloaded by clicking here.

For more details on Qt, check out its wikipedia page.

Aptitude Questions 3

noreply@blogger.com (Anonymous) — Fri, 28 Oct 2011 12:55:00 +0000

Aptitude questions to sharpen your minds... every week. Enjoy this week's questions. Answers coming friday!

1. There is a safe with a 5 digit number as the key. The 4th digit is 4 greater than the second digit, while the 3rd digit is 3 less than the 2nd digit. The 1st digit is thrice the last digit. There are 3 pairs whose sum is 11.

Find the number.

2.A series comprising of alphabets contains 13 letters. The first seven letters in the given series are A, E, F, H, I, L, M

Can you find the next two letters?

3.Which number in the series does not fit in the given series:

1 4 3 16 6 36 7 64 9 100

4.The sum of their (father, mother and son) ages is 70. The father is 6 times as old as the son. When the sum of their ages is twice 70, the father will be twice as old as the son.

How old is the mother?

5.A rich man died. In his will, he has divided his gold coins among his 5 sons, 5 daughters and a manager.

According to his will: First give one coin to manager. 1/5th of the remaining to the elder son. Now give one coin to the manager and 1/5th of the remaining to second son and so on..... After giving coins to 5th son, divided the remaining coins among five daughters equally. All should get full coins. Find the minimum number of coins he has?

6.There are 10 boxes containing 10 balls each. 9 boxes contain 10 balls of 10 kg each and one box contains 10 balls of 9 kg each. Tool is available for proper weighing. How can you find out the box containing 9 kg balls?

You are allowed to weigh only once. You can remove balls from the boxes. All balls are of same size and color.

7.Next number in the series is 1, 2, 4, 13, 31, 112, ?

8.What two numbers comes next in this series?:

1, 2, 3, 6, 7, 14, 15, 30, 31, ? ?

9.The minute and the hour hand of a watch meet every 65 minutes.
How much does the watch lose or gain time and by how much?

10. 3 blocks are chosen randomly on a chessboard. What is the probability that they are in the same diagonal?

Aptitude answers 2

noreply@blogger.com (Anonymous) — Fri, 28 Oct 2011 05:16:00 +0000

Here are the answers to the last week's aptitude questions. Read more for the answers. Refer here for the corresponding questions!!!

1.Answer:
(a) 0 %
Explanation:
Since 3x / 2 = x / (2 / 3)

2.Answer:
(c) 1
Explanation:
a percent of b : (a/100) * b
b percent of a : (b/100) * a
a percent of b divided by b percent of a : ((a / 100 )*b) / (b/100) * a ))=1

3.Answer:
(c) 5.3 %
Explanation:
He sells 950 grams of pulses and gains 50 grams.
If he sells 100 grams of pulses then he will gain (50 / 950) *100 =5.26

4.Answer:
(d) none of the above
Explanation:
Since every alternative letter starting from B of the English alphabet is
written in small letter, the letters written in small letter are b, d, f...
In the first two answers the letter E is written in both small & capital
letters, so they are not the correct answers. But in third and fourth answers the
letter is written in small letter instead capital letter, so they are not the answer.

5.Answer:
(c) x = 4
Explanation:
Since the side of the square is x + 2, its perimeter = 4 (x + 2) = 4x + 8
Since the side of the equilateral triangle is 2x, its perimeter = 3 * 2x = 6x
Also, the perimeters of both are equal.
(i.e.) 4x + 8 = 6x
(i.e.) 2x = 8 „» x = 4.

6.Answer:
(c) G.
Explanation:
The order in which they are climbing is R – G – K – H – J
15 – 18

7.Answer :
a) 336
Explanation : The series is 1.2.3, 2.3.4, 3.4.5, 4.5.6, 5.6.7, ..... ( '.' means product)

8.Answer :
(b) 1 hr 12 min
Explanation : The fast typist's work done in 1 hr = 1/2
The slow typist's work done in 1 hr = 1/3
If they work combinely, work done in 1 hr = 1/2+1/3 = 5/6
So, the work will be completed in 6/5 hours. i.e., 1+1/5 hours = 1hr 12 min

9.Answer :
(a) 35392
Explanation : The number closest to 100 which is greater than 100 and
divisible by 14 is 112, which is the first term of the series which has to be summed.
The number closest to 1000 which is less than 1000 and divisible by 14
is 994, which is the last term of the series.
112 + 126 + .... + 994 = 14(8+9+ ... + 71) = 35392

10.Answer :
(b) 1 P.M.
Explanation : 24 billion hours later, it would be 9 P.M. and 8 hours before
that it would be 1 P.M.

Aptitude Questions 2

noreply@blogger.com (Anonymous) — Fri, 21 Oct 2011 19:45:00 +0000

Aptitude questions to sharpen your minds... every week. Enjoy this week's questions. Answers coming friday!

1.A student divided a number by 2/3 when he required to multiply by 3/2.
Calculate the percentage of error in his result.

a) 0%
b) 1%
c) 5%
d)8%

2.what is a percent of b divided by b percent of a?

(a) a
(b) b
(c) 1
(d) 10
(e) 100

3.A dishonest shopkeeper professes to sell pulses at the cost price, but he uses a false weight of 950gm. for a kg. His gain is …%.

a) 3%
b)4.5%
c) 5.3%
d) 8%

4.If every alternative letter starting from B of the English alphabet is written in small letter, rest all are written in capital letters, how the month “September” be written.

a) SeptEMbEr
b) SEpTeMBEr
c) SeptembeR
d) None of the above.

5. The length of the side of a square is represented by x+2. The length of the side of an equilateral triangle is 2x. If the square and the equilateral triangle have equal perimeter, then the value of x is _______.

a) 1
b) 3
c) 4
d) 2/3

6.Five boys were climbing a hill. J was following H. R was just ahead of G. K
was between G & H. They were climbing up in a column. Who was the
second?

a) H
b) R
c) G
d) J

7.For the following, find the next term in the series: 6, 24, 60,120, 210

a) 336
b) 366
c) 330
d) 660

8.A fast typist can type some matter in 2 hours and a slow typist can type the same in 3 hours. If both type combinely, in how much time will they finish?

a) 1 hr
b) 1 hr 12 min
c) 2 hr
d) 3 hr

9.What is the sum of all numbers between 100 and 1000 which are divisible by 14 ?

a) 35392
b) 35390
c) 35010
d) 34390

10.If time at this moment is 9 P.M., what will be the time 23999999992 hours later?

a) 5 AM
b)1 PM
c) 8 PM
d)8 AM

Aptitude Answers 1

noreply@blogger.com (Anonymous) — Fri, 21 Oct 2011 19:16:00 +0000

Here are the answers to the last week's aptitude questions. Read more for the answers. Refer here for the corresponding questions!!!

1.Ans: (b)20:36:63

Method:
             4*9/4:7*9/4
             5:9:63/4
             20:36:63

2.Ans: (a) 4*4/9 days (or) 40/9. days

Method:
           A--> 8days --> 1 day work=1/8
           B-->10days =1/10
            A+B = 1/8+1/10
                     = 9/40
             40/9 = 4*4/9 days.

3.Ans:8+8+8+88+888=1000

4.Ans: (c) Sunday

Method:
           28 may 2006 =2005 year + period from 1.1.2006 to 28.5.2006
           Odd days in 1600 year = 0
           Odd days in 400 year = 0
           5 year = (4 ordinary year + 1 leap year)
                      = (4*1+1*2)
                      = 6 odd days.
            Jan      feb      mar     apr     may
            31   + 28 + 31 + 30 + 28 = 148 days.
                    148 days = (21 weeks + 1 day)
                                   = 1 odd day.
Total Number of odd days = 0+0+6+1 =7
              Therefore there is no odd day. Hence it's Sunday.

5.Ans: (d) 100%

Method:
           C.P be RS *   and S.P be RS .Y
           3(y-x) = 2y-x = y =2x
           Profit =RS(y-x) =2x-x
                      =RS.x
Profit% =(x/x*100)% =100%

6.Ans:(b) 28

Method:
          n(n-1)/2 = number of hand shakes.
                8(7)/2 = 28
7. Ans:
           (d) 2800

8.Ans:
(b) M
Method:
E=5(alphabet)
M=13
H=8
(5+8=13)
Same method I=9
D=4
(9+4=13)
So ans is M

9. Ans:
   4/4+4*4=20
Method:
   4/4=1+4=5*4=20.
10. Ans:
           (a) Cost price of horse = Rs. 400 & the cost price of cart = 200.
Method:-

Let x be the cost price of the horse and y be the cost price of the cart.
In the first sale there is no loss or profit. (i.e.) The loss obtained is equal to the
gain.
Therefore (10/100) * x = (20/100) * y
X = 2 * y -----------------(1)
In the second sale, he lost Rs. 10. (i.e.) The loss is greater than the profit by
Rs. 10.
Therefore (5 / 100) * x = (5 / 100) * y + 10 -------(2)
Substituting (1) in (2) we get
(10 / 100) * y = (5 / 100) * y + 10
(5 / 100) * y = 10
y = 200
From (1) 2 * 200 = x = 400.

Keyboard Shortcuts

noreply@blogger.com (Unknown) — Mon, 17 Oct 2011 17:26:00 +0000

Here's an attempt at listing out all the keyboard shortcuts that are available for different applications over various platforms. Feel free to comment in the ones I've missed out.:

General Shortcuts

CTRL+C (Copy)
CTRL+X (Cut)
CTRL+V (Paste)
CTRL+Z (Undo)
DELETE (Delete)
SHIFT+DELETE (Delete the selected item permanently without placing the item in the Recycle Bin)
CTRL while dragging an item (Copy the selected item)
CTRL+SHIFT while dragging an item (Create a shortcut to the selected item)
F2 key (Rename the selected item)
CTRL+RIGHT ARROW (Move the insertion point to the beginning of the next word)
CTRL+LEFT ARROW (Move the insertion point to the beginning of the previous word)
CTRL+DOWN ARROW (Move the insertion point to the beginning of the next paragraph)
CTRL+UP ARROW (Move the insertion point to the beginning of the previous paragraph)
CTRL+SHIFT with any of the arrow keys (Highlight a block of text)
SHIFT with any of the arrow keys (Select more than one item in a window or on the desktop, or select text in a document)
CTRL+A (Select all)
F3 key (Search for a file or a folder)
ALT+ENTER (View the properties for the selected item)
ALT+F4 (Close the active item, or quit the active program)
ALT+ENTER (Display the properties of the selected object)
ALT+SPACEBAR (Open the shortcut menu for the active window)
CTRL+F4 (Close the active document in programs that enable you to have multiple documents open simultaneously)
ALT+TAB (Switch between the open items)
ALT+ESC (Cycle through items in the order that they had been opened)
F6 key (Cycle through the screen elements in a window or on the desktop)
F4 key (Display the Address bar list in My Computer or Windows Explorer)
SHIFT+F10 (Display the shortcut menu for the selected item)
ALT+SPACEBAR (Display the System menu for the active window)
CTRL+ESC (Display the Start menu)
ALT+Underlined letter in a menu name (Display the corresponding menu)
Underlined letter in a command name on an open menu (Perform the corresponding command)
F10 key (Activate the menu bar in the active program)
RIGHT ARROW (Open the next menu to the right, or open a submenu)
LEFT ARROW (Open the next menu to the left, or close a submenu)
F5 key (Update the active window)
BACKSPACE (View the folder one level up in My Computer or Windows Explorer)
ESC (Cancel the current task)
SHIFT when you insert a CD-ROM into the CD-ROM drive (Prevent the CD-ROM from automatically playing)
CTRL+SHIFT+ESC (Open Task Manager)

Dialog box keyboard shortcuts

If you press SHIFT+F8 in extended selection list boxes, you enable extended selection mode. In this mode, you can use an arrow key to move a cursor without changing the selection. You can press CTRL+SPACEBAR or SHIFT+SPACEBAR to adjust the selection. To cancel extended selection mode, press SHIFT+F8 again. Extended selection mode cancels itself when you move the focus to another control.

CTRL+TAB (Move forward through the tabs)
CTRL+SHIFT+TAB (Move backward through the tabs)
TAB (Move forward through the options)
SHIFT+TAB (Move backward through the options)
ALT+Underlined letter (Perform the corresponding command or select the corresponding option)
ENTER (Perform the command for the active option or button)
SPACEBAR (Select or clear the check box if the active option is a check box)
Arrow keys (Select a button if the active option is a group of option buttons)
F1 key (Display Help)
F4 key (Display the items in the active list)
BACKSPACE (Open a folder one level up if a folder is selected in the Save As or Open dialog box)

Microsoft natural keyboard shortcuts

Windows Logo (Display or hide the Start menu)
Windows Logo+BREAK (Display the System Properties dialog box)
Windows Logo+D (Display the desktop)
Windows Logo+M (Minimize all of the windows)
Windows Logo+SHIFT+M (Restore the minimized windows)
Windows Logo+E (Open My Computer)
Windows Logo+F (Search for a file or a folder)
CTRL+Windows Logo+F (Search for computers)
Windows Logo+F1 (Display Windows Help)
Windows Logo+ L (Lock the keyboard)
Windows Logo+R (Open the Run dialog box)
Windows Logo+U (Open Utility Manager)

Accessibility keyboard shortcuts

Right SHIFT for eight seconds (Switch FilterKeys either on or off)
Left ALT+left SHIFT+PRINT SCREEN (Switch High Contrast either on or off)
Left ALT+left SHIFT+NUM LOCK (Switch the MouseKeys either on or off)
SHIFT five times (Switch the StickyKeys either on or off)
NUM LOCK for five seconds (Switch the ToggleKeys either on or off)
Windows Logo +U (Open Utility Manager)

Windows Explorer keyboard shortcuts

END (Display the bottom of the active window)
HOME (Display the top of the active window)
NUM LOCK+Asterisk sign (*) (Display all of the subfolders that are under the selected folder)
NUM LOCK+Plus sign (+) (Display the contents of the selected folder)
NUM LOCK+Minus sign (-) (Collapse the selected folder)
LEFT ARROW (Collapse the current selection if it is expanded, or select the parent folder)
RIGHT ARROW (Display the current selection if it is collapsed, or select the first subfolder)

Shortcut keys for Character Map

After you double-click a character on the grid of characters, you can move through the grid by using the keyboard shortcuts:

RIGHT ARROW (Move to the right or to the beginning of the next line)
LEFT ARROW (Move to the left or to the end of the previous line)
UP ARROW (Move up one row)
DOWN ARROW (Move down one row)
PAGE UP (Move up one screen at a time)
PAGE DOWN (Move down one screen at a time)
HOME (Move to the beginning of the line)
END (Move to the end of the line)
CTRL+HOME (Move to the first character)
CTRL+END (Move to the last character)
SPACEBAR (Switch between Enlarged and Normal mode when a character is selected)

Microsoft Management Console (MMC) - Main Window Keyboard Shortcuts

CTRL+O (Open a saved console)
CTRL+N (Open a new console)
CTRL+S (Save the open console)
CTRL+M (Add or remove a console item)
CTRL+W (Open a new window)
F5 key (Update the content of all console windows)
ALT+SPACEBAR (Display the MMC window menu)
ALT+F4 (Close the console)
ALT+A (Display the Action menu)
ALT+V (Display the View menu)
ALT+F (Display the File menu)
ALT+O (Display the Favorites menu)

MMC console window keyboard shortcuts

CTRL+P (Print the current page or active pane)
ALT+Minus sign (-) (Display the window menu for the active console window)
SHIFT+F10 (Display the Action shortcut menu for the selected item)
F1 key (Open the Help topic, if any, for the selected item)
F5 key (Update the content of all console windows)
CTRL+F10 (Maximize the active console window)
CTRL+F5 (Restore the active console window)
ALT+ENTER (Display the Properties dialog box, if any, for the selected item)
F2 key (Rename the selected item)
CTRL+F4 (Close the active console window. When a console has only one console window, this shortcut closes the console)

Remote desktop connection navigation

CTRL+ALT+END (Open the Microsoft Windows NT Security dialog box)
ALT+PAGE UP (Switch between programs from left to right)
ALT+PAGE DOWN (Switch between programs from right to left)
ALT+INSERT (Cycle through the programs in most recently used order)
ALT+HOME (Display the Start menu)
CTRL+ALT+BREAK (Switch the client computer between a window and a full screen)
ALT+DELETE (Display the Windows menu)
CTRL+ALT+Minus sign (-) (Place a snapshot of the entire client window area on the Terminal server clipboard and provide the same functionality as pressing ALT+PRINT SCREEN on a local computer.)
CTRL+ALT+Plus sign (+) (Place a snapshot of the active window in the client on the Terminal server clipboard and provide the same functionality as pressing PRINT SCREEN on a local computer.)

Microsoft Internet Explorer navigation

CTRL+B (Open the Organize Favorites dialog box)
CTRL+E (Open the Search bar)
CTRL+F (Start the Find utility)
CTRL+H (Open the History bar)
CTRL+I (Open the Favorites bar)
CTRL+L (Open the Open dialog box)
CTRL+N (Start another instance of the browser with the same Web address)
CTRL+O (Open the Open dialog box, the same as CTRL+L)
CTRL+P (Open the Print dialog box)
CTRL+R (Update the current Web page)
CTRL+W (Close the current window)

Aptitude Questions 1

noreply@blogger.com (Anonymous) — Sat, 15 Oct 2011 10:30:00 +0000

Aptitude questions to sharpen your minds... every week. Enjoy this week's questions. Answers coming friday!

1) A : B = 5 : 9
B : C = 4 : 7
A : B : C = ?

a) 21 : 36 : 63
b) 20 : 36 : 63
c) 21 : 30 : 63
d) 216 : 31 : 44

2) A takes 8 days to do a job B takes 10 days to do same job. How long should it take both A and B working together but independently to do the same job?

a) 40/9
b) 44/7
c) 40
d) 45

3) How can you add eight 8's to get the number 1,000? (only use addition)

4) What was the day of the week on 28th may 2006?

a) monday
b) tuesday
c) sunday
d) friday

5) If selling price is doubled, the profit triples find the profit %

a) 10%
b) 80%
c) 40%
d) 100%

6) In a commitee, 8 persons shake each others' hand. How many handshakes in total have taken place?

a) 8
b) 28
c) 25
d) 15

7) The average of 5 consective even numbers A,B,C,D and E is 52 what is the product of B and E?

a) 2912
b) 2688
c) 3024
d) 2800

8) E M H
N O A
I ? D

a) F
b) M
c) C
d) X

9) 4 ? 4 ? 4 ? 4 = 20 use +,-,/,* and solve it.

10) A man bought a horse and a cart. If he sold the horse at 10 % loss and the cart
at 20 % gain, he would not lose anything; but if he sold the horse at 5% loss
and the cart at 5% gain, he would lose Rs. 10 in the bargain. The amount paid
by him was Rs._______ for the horse and Rs.________ for the cart.

a) 400,200
b) 800,400
c) 200,400
d)1000,400

Validation in windows application in C#

noreply@blogger.com (black parody) — Fri, 14 Oct 2011 09:07:00 +0000

Whenever we create an application, some forms need specific entries. For example, phone numbers must be all numeric, whilst email ID must have a @ symbol followed somewhere by a . symbol. For these purposes, no automatic validators are provided for windows applications. Hence, we must manually give validations to these fields.

There are many logical routes to valication. The following is the validation code that I follow. Hope it helps you too. In case of any doubts or suggestions, kindly feel free to comment or mail me at nardz07@gmail.com.

Personally I find it best to write my validation code in the keypress event of a textbox, as it simply prevents the textbox from accepting any value that is outside the parameter for entry.

Let us first study the numeric validation. It must accept only numeric values, and not any alphabets or special characters. The following is my code for the keypress event of home phone number textbox:

private void txthmno_KeyPress(object sender, KeyPressEventArgs e)
{
try
{
if (!char.IsControl(e.KeyChar) && !char.IsDigit(e.KeyChar))
{
e.Handled = true;
}
}
catch
{

}
}

Here, I have used the if conditional statement... which translates to - If the key pressed is not a control key, AND not a digit key, then capture it as an exception and handle it. Otherwise, allow the keypress to be read in the textbox.

Now, say I need someone to enter their name, and no special characters. Then in that case, I must ensure that only alphabets are allowed. Here, I have implemented this in the keypress event for the first name textbox:

private void txtfrstnm_KeyPress(object sender, KeyPressEventArgs e)
{
if (!char.IsControl(e.KeyChar) && !char.IsLetter(e.KeyChar))
{
e.Handled = true;
}
}

In this case I simply replaced IsDigit with IsLetter... so unless the key pressed is a control key (enter or backspace or delete) or an alphabet, the textbox will not accept a value.

Now let us take another custom scenario, a little different than this. Say you are creating an application that must be able to read an email entry and tell whether it is a valid address or not. Clearly we cannot tell that without running through the databases of the said email distributor's server. However, email IDs in general have a format, and we can set a validation to ensure those requirements are met. Again, there is not a word limit or a restriction to any general set of characters, so we cannot simply disable certain keystrokes. What we can do however, is raise error dialogs.

This is a sample of what I did when I tried out an email entry textbox validation. I use the validating event of the text box, so the error will not be raised till we leave the textbox:

private void textBox1_Validating(object sender, CancelEventArgs e)
{
    Regex regex = new Regex("@([a-zA-Z0-9_\-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([a-zA-Z0-9\-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})");
    if (regex.IsMatch(textBox1.Text))
    {
        errorProvider1.SetError(textBox1, String.Empty);
    }
    else
    {
        errorProvider1.SetError(textBox1,
              "This is not valid date");
    }
}.

As you might have noticed, we have used a concept called regex, which stands for regular expression. Regular expression is a concept that, simply put, lists out exactly what all characters are allowed.

For your knowledge, here is the regex for:

Date:

(?<Month>\d{1,2})/(?<Day>\d{1,2})/(?<Year>(?:\d{4}|\d{2}))

Phone Number:

\((?<AreaCode>\d{3})\)\s*(?<Number>\d{3}(?:-|\s*)\d{4})

Email ID:

([a-zA-Z0-9_\-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([a-zA-Z0-9\-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})

You might have noticed that I have preceded the regular expression with an @ symbol. This is because, regular expression is, by default a concept oriented in VB. To make it compatible in C#, where this code was written, we add a @ symbol.

The concept behind the validating and the validated events is the use of a concept called error provider. It is one control that sits in the background of the application and helps raise errors. But more on that later. For now, adieu.

Ten Important Tips For Java Users

noreply@blogger.com (Unknown) — Thu, 13 Oct 2011 19:10:00 +0000

There are some protocols that when followed differentiate a good program from a mediocre program. Here are some tips that will help you become good Java programmers:

Tip 1: Avoid creating unnecessary objects and always prefer to do Lazy Initialization

Object creation in Java is one of the most expensive operation in terms of memory utilization and performance impact. It is thus advisable to create or initialize an object only when it is required in the code.

public class Countries

{

private List countries;

public List getCountries()

{

        //initialize
only when required

if(null == countries)

{

countries = new ArrayList();

}

return countries;

}

Tip 2: Never make an instance fields of class public

Making a class field public can cause lot of issues in a program. For instance you may have a class called MyCalender. This class contains an array of String weekdays. You may have assume that this array will always contain 7 names of weekdays. But as this array is public, it may be accessed by anyone. Someone by mistake also may change the value and insert a bug!

public class MyCalender

{

public String[] weekdays =

{"Sun", "Mon", "Tue", "Thu", "Fri", "Sat", "Sun"};

    //some
code

}

Best approach as many of you already know is to always make the field private and add a getter method to access the elements.

private String[] weekdays =

{"Sun", "Mon", "Tue", "Thu", "Fri", "Sat", "Sun"};

public String[] getWeekdays()

{

return weekdays;

}

But writing getter method does not exactly solve our problem. The array is still accessible. Best way to make it unmodifiable is to return a clone of array instead of array itself. Thus the getter method will be changed to.

public String[] getWeekdays()

{

return weekdays.clone();
}

Tip 3: Always try to minimize Mutability of a class

Making a class immutable is to make it unmodifiable. The information the class preserve will stay as it is through out the lifetime of the class. Immutable classes are simple, they are easy to manage. They are thread safe. They make great building blocks for other objects.

However creating immutable objects can hit performance of an app. So always choose wisely if you want your class to be immutable or not. Always try to make a small class with fewer fields immutable.

To make a class immutable you can define its all constructors private and then create a public static method
to initialize and object and return it.

public class Employee

{

private String firstName;

private String lastName;

    //private
default constructor

private Employee(String firstName, String lastName)
{

this.firstName = firstName;

this.lastName = lastName;

}

public static Employee valueOf (String firstName, String lastName)
{

return new Employee(firstName, lastName);

}

Tip 4: Try to prefer Interfaces instead of Abstract classes

First you can not inherit multiple classes in Java but you can definitely implements multiple interfaces. It’s very easy to change the implementation of an existing class and add implementation of one more interface rather then changing full hierarchy of class.

Again if you are 100% sure what methods an interface will have, then only start coding that interface. As it is very difficult to add a new method in an existing interface without breaking the code that has already implemented it. On contrary a new method can be easily added in Abstract class without breaking existing functionality.

Tip 5: Always try to limit the scope of Local variable

Local variables are great. But sometimes we may insert some bugs due to copy paste of old code. Minimizing the scope of a local variable makes code more readable, less error prone and also improves the maintainability of the code.

Thus, declare a variable only when needed just before its use.

Always initialize a local variable upon its declaration. If not possible at least make the local instance assigned null value.

Tip 6: Try to use standard library instead of writing your own from scratch

Writing code is fun. But “do not reinvent the wheel”. It is very advisable to use an existing standard library which is already tested, debugged and used by others. This not only improves the efficiency of programmer but also reduces chances of adding new bugs in your code. Also using a standard library makes code readable and maintainable.

For instance Google has just released a new library Google Collections that can be used if you want to add advance collection functionality in your code.

Tip 7: Wherever possible try to use Primitive types instead of Wrapper classes

Wrapper classes are great. But at same time they are slow. Primitive types are just values, whereas Wrapper classes are stores information about complete class.

Sometimes a programmer may add bug in the code by using wrapper due to oversight. For example, in below example:

int x = 10;

int y = 10;

Integer x1 = new Integer(10);

Integer y1 = new Integer(10);

System.out.println(x == y);

System.out.println(x1 == y1);

The first sop will print true whereas the second one will print false. The problem is when comparing two wrapper class objects we can’t use == operator. It will compare the reference of object and not its actual value.

Also if you are using a wrapper class object then never forget to initialize it to a default value. As by default all wrapper class objects are initialized to null.

Boolean flag;

if(flag == true)
{

System.out.println(

"Flag
is set"

);

}
else
{

System.out.println(

"Flag
is not set"

);

}

The above code will give a NullPointerException as it tries to box the values before comparing with true and as its null.

Tip 8: Use Strings with utmost care

Always carefully use Strings in your code. A simple concatenation of strings can reduce performance of program. For example if we concatenate strings using + operator in a for loop then everytime + is used, it creates a new String object. This will affect both memory usage and performance time.

Also whenever you want to instantiate a String object, never use its constructor but always instantiate it directly. For example:

//slow instantiation

String slow = new String(

"Yet another string
object"

);

//fast instantiation
String fast = "Yet another string object";

Tip 9: Always return empty Collections and Arrays instead of null

Whenever your method is returning a collection element or an array, always make sure you return empty array/collection and not null. This will save a lot of if else testing for null elements. For instance in below example we have a getter method that returns employee name. If the name is null it simply return blank string “”.

public String getEmployeeName()
{

return (null==employeeName ? "": employeeName);
}

Tip 10: Defensive copies are savior

Defensive copies are the clone objects created to avoid mutation of an object. For example in below code we have defined a Student class which has a private field birth date that is initialized when the object is constructed.

public class Student

{

private Date birthDate;

public Student(birthDate) {

this.birthDate = birthDate;

}

public Date getBirthDate() {

return this.birthDate;

}

Now we may have some other code that uses the Student object.

public static void main(String []arg) {

Date birthDate = new Date();

Student student = new Student(birthDate);

birthDate.setYear(2019);

System.out.println(student.getBirthDate());

}

In above code we just created a Student object with some default birthdate. But then we changed the value of year of the birthdate. Thus when we print the birth date, its year was changed to 2019!

To avoid such cases, we can use Defensive copies mechanism. Change the constructor of Student class to following.

public Student(birthDate)

{

this.birthDate = new Date(birthDate);

}

This ensures we have another copy of birthdate that we use in Student class.

Two bonus Tips

Here are two bonus Java best practice Tips for you.

Tip 11: Never let exception come out of finally block

Finally blocks should never have code that throws exception. Always make sure finally clause does not throw exception. If you have some code in finally block that does throw exception, then log the exception properly and never let it come out :)

Tip 12: Never throw “Exception”

Never throw java.lang.Exception directly. It defeats the purpose of using checked Exceptions. Also there is no useful information getting conveyed in caller method.

how to ensure ranking in sql

noreply@blogger.com (black parody) — Thu, 13 Oct 2011 16:43:00 +0000

Whilst using mysql, I was inspired by our faculty to figure out how to assign ranks to the entries. A little bit of internet browsing, a lot of head scratching, and some innovatively redundant use of table manipulation later, I succeeded.

Point to be noted, we MUST not use the 'rank' structure of transact-sql. Instead we use and manipulate simple sql queries.

Here is the tutorial, please contact me at nardz07@gmail.com

Suppose we have a simple table:

This table emp has ten records as shown above that need to be sorted.

Firstly, if we do not use the transact-sql rank over() command, that is available only in sql server, we must manipulate the table using simpler commands.

Let us first see the simplest way to go about it.

Simply enter the following query to get rank:

select a.eid, a.ename,a.esalary,count(b.esalary) rank from emp a, emp b where a.esalary <= b.esalary or (a.esalary = b.esalary and a.ename = b.ename) group by a.ename,a.esalary order by a.esalary desc, a.ename desc;

This will give us the result:

Before I explain the code, let us clear the requirements. The ranking must be such that the highest paid employee gets the most significant (numerically the smallest) rank.

No two employees must share the same rank unless they draw equal salary, and then it must be ensured their rank placing affects those drawing lesser salary than them.

That is, say if two people are tied after the second place, then either both must be placed third/fourth and the person coming in next must be 5th place only.

Now, let us study the coding.

To display rank in SQL, the idea is to do a self-join, list out the results in order, and do a count on the number of records that's listed ahead of (and including) the record of interest.

Let's focus on the WHERE clause. The first part of the clause, (a.esalary <= b.esalary), makes sure we are only counting the number of occurrences where the value in the Sales column is less than or equal to itself. If there are no duplicate values in the Sales column, this portion of the WHERE clause by itself would be sufficient to generate the correct ranking.

The second part of the clause, (a.esalary=b.esalary and a.ename = b.ename), ensures that when there are duplicate values in the Sales column, each one would get the correct rank.

What must be noted here, is that we have completely avoided using any kind of join in the above code, even though we technically are following the self join logic.

More detailed explanation and analysis into this later. Please contact me with your suggestions and doubts. Till next time, mate!

Add a Splash Screen to Your C# Windows Application Project

noreply@blogger.com (Ignatius, Tony) — Tue, 11 Oct 2011 10:47:00 +0000

How to create a splash screen in C#

Tutorial: How to create a splash screen in C#

Time: 5 minutes

Experience needed: Basic understanding of Threads and the flow of applications

In this tutorial you will learn how to create an application that displays a splash form for x seconds.

The benefits for this are: if you have a form that takes a while to load up (for insastance one that does a lot of Database interaction) the user will sit there wondering why your app is not open yet.

With a splash screen you can give the user something pretty to look at to keep them happy.

From here on in I assume you have a created a new project/solution and/or a new form.

Step 1 - Setup

If you are in Design View press F7 or click View then Code to swith to code view.

At the top of the source code you will see lines of code similar to this

Code:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;

Add the following line to that code

Code:

using System.Threading;

You should now have something that looks like this

Code:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Threading;

Step 2 - Setting up the splash screen

Add a new Windows Form to your application. This will be your splash screen. I will leave you alone for 5 minutes so you can make it jazzy!

(5 minutes later).

Welcome back. So, we have our splash form, we have our main form. Now we need to tell our program we want to open our splash screen before our main screen.

In the source code of your main form, look for code like this

Code:

public Form1()
        {
            InitializeComponent();
         }

Here we are going to create a new Thread which will trigger the creation and showing of our splash form. Type the following code below InitializeComponent().

Code:

Thread t1 = new Thread(new ThreadStart(SplashForm));
            t1.Start();
            Thread.Sleep(5000); // The amount of time we want our splash form visible
            t1.Abort();
            Thread.Sleep(1000);

Now we should have code that looks like this

Code:

public Form1()
        {
            InitializeComponent();

            Thread t1 = new Thread(new ThreadStart(SplashForm));
            t1.Start();
            Thread.Sleep(5000); // 5 seconds
            t1.Abort();
            Thread.Sleep(1000);
        }

One thing may be puzzling you there, whats SplashForm? SplashForm is the method that will open our splash form. Heres the code for that.

Code:

private void SplashForm()
        {
            SplashForm newSplashForm = new SplashForm();
            newSplashForm.ShowDialog();
            newSplashForm.Dispose();
        }

So when the thread starts, the above code wil run.

And there you have it, you have made a splash screen in C#.

FYI: There are several ways this could have been done, I used Threads as I was already using them for another part of a project. Another popular way would be to use a timer.

Happy Programming.

Steve's Job Gets Over :(

noreply@blogger.com (Anonymous) — Mon, 10 Oct 2011 13:22:00 +0000

Steve Jobs, co-founder and the former CEO of the world reputed computer firm Apple (AAPL) bids a good bye to his followers at the age of 56. The mastermind behind Apple's iPhone, iPad, iPod, iMac and iTunes, has died in California after a lifely battle against his pancreatic cancer.

Apple has lost a visionary and a creative genius. Steve more than perfect human.
Jobs died peacefully, surrounded by family members, his family said in a statement. In recent years Jobs had fought a form of pancreatic cancer and had a liver transplant.

"Steve's brilliance, passion and energy were the source of countless innovations that enrich and improve all of our lives,".

"The world is immeasurably better because of Steve. His greatest love was for his wife, Laurene, and his family. Our hearts go out to them and to all who were touched by his extraordinary gifts."

Jobs co-founded Apple Computer in 1976 and, with his childhood friend Steve Wozniak, marketed what was considered the world's first successful personal computer, the Apple II.

Industry watchers called Jobs a master innovator -- perhaps on a par with Thomas Edison -- changing the worlds of computing, recorded music and communications.

Broadcom wireless 802.11 Installing Wi-fi Broadcom 802.11 driver for fedora 15

noreply@blogger.com (black parody) — Mon, 10 Oct 2011 12:56:00 +0000

As mentioned earlier, I recently installed fedora 15 on my system. Unfortunately, the packages did not include the drivers to my Wireless LAN card. Hence I was unable to use the newly introduced wi-fi feature of fedora. Many of my friends, I presume must have faced the same problem, so here is a little trick I used to get my wi-fi on!

Please mail me at nardz07@gmail.com with any suggestions or doubts.

Broadcom wireless driver can be installed from source package or you can install the pre-compiled version. In this post you can find information on how to install pre-compiled version using yum install. This package can be install the same way how we install Firefox 6 or UNRAR in Fedora 15 / 14. If you have already upgraded your rpmfusion free and non-free release in your system then skip the dependencies.

DEPENDENCIES

Run the following command in terminal one by one and type the password for the root when prompted.

For rpmfusion free release

$ su -c 'rpm -Uvh http://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-stable.noarch.rpm'

For rpmfusion non free release

$ su -c 'rpm -Uvh http://download1.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-stable.noarch.rpm'

Once you have upgraded the rpmfusion free and non-free release in your system then update the system using the following command. Type the password for the user when prompted.

$ sudo yum update

INSTALLING

To install the driver run the following command in terminal.

$ sudo yum install kmod-wl

Now restart your system. It should work.

Hope this will be helpful for you!!!

Till Next time, then! :)