Arrow function helps programmers intending to write declarative code with Javascript. While everyone may have different feelings for this new addition to the Javascript/ES6 but at the same time whatever camp you belong to you, you will have to deal with and deal with variations of Arrow Function.

Why you need to know this?

Theoretically you don't need to learn to use arrow function at all. You can do everything with good old "function" that you have been doing since you started writing your first Javascript code. It could be advantageous in some cases but you can get away without using them. But even if you don't use it right now, you might end up using arrow functions in future or you might have to maintain code that was written by someone who loved using arrow functions.
So there is always wisdom in learning, knowledge is power!!

Now, without spending more time in introduction, we will get straight to the business and talk about variations.

No Parameters

() => 7

var fn = () => 7
// To run: fn()
// expected output: 7  

Single Parameter

p => p*p

(p) => p*p

var fn = (p) => p * p
// To run: fn(5)
// expected output: 25  

Multiple Parameters

(p1, p2) => p1+p2

var fn = (p) => p * p
// To run: fn(5)
// expected output: 25  

Using Gather Operator or Rest Parameters

(...p) => expression

var fn = (...p) =>  p.map(Math.sqrt);
// To run: fn(25, 16)
// expected output: [5, 4]

Using Curly Brackets for Concise Function Body

(...p) => expression

var fn = (p1, p2) =>  { return p1 * p2; }
// To run: fn(5, 6)
// expected output: 30

var fn = (...params) =>  {
let output = 0;
for(let param of params) output += param;
return output;
}
// Usage: fn(1,2,3)
// expected output: 6
// Using with spread operator
let input = [1, 2, 3, 6];
fn(...input)
// output: 12

Returning Object

(p1, p2) => ({"param1": p1, "param2": p2})

// Wrong usage: results in Javascript syntax error
let fn = (p1, p2) => {"param1": p1, "param2": p2}
// Correct usage
let fn = (p1, p2) => ({"param1": p1, "param2": p2})
// To run: fn(10, 20)
// expected output: {"param1": 100, "param2": 200}  

What you can't do with Arrow Function?

In the end;

• They are anonymous and so will show up as anonymous functions in stack trace, you can store them in a variable (like we did in all examples above) and it will use name inference.
• You can't easily self reference to it (think about recursion)

Credits / References

Feel free to shout out your experience with new features of ES6 and your thoughts on arrow function in comments below.

DevOps is not a silver bullet to fix all the problems between Development (Developers + QA) and Operations team and things won't change overnight. To cut long story short, I have compiled a presentation last year for one company which was looking forward to create a space for DevOps in their organization - initially to experiment and start by eating their own dog food and then using it as a service to market and gain new business by providing DevOps as a Service.

I would highly recommend to watch this presentation to anyone who is either looking forward to make a career move towards DevOps or a business who is planning to start a DevOps within the organization or a company who is planning to jump into DevOps as a Service provider or even if you're just an enthusiast who is looking forward to know more on the topic.

Liked the presentation? I would like to listen to your comments about the presentation and your experiences in the DevOps space.

Or just feel free to ask a question - below in the comments section.

I am sure there are many third party apps available which enable this feature other than Power Toys (by Microsoft) and I have used them in past but did not wanted to bloat my system with more tools. Then I came across an article on the Internet showing 10 ways to open command prompt in Windows 10 and there I found my now favorite trick to open Windows CLI.

Look at this, go to address-bar in Windows Explorer and type in just 3 letter "CMD" and it opens up Windows Command-line right there with your current directory as the active/working directory in command-prompt instance.

This is really nice hidden feature and using it will save you from the hell of navigating to your working directory.

Similarly if you want to open "command-prompt as administrator" with working directory in Windows Explorer just navigate to File > Open command prompt > Open command prompt as administrator. Same goes for Windows PowerShell as well, look at the screen capture below;

I hope this simple yet hidden trick will be helpful to you and save your few minutes a day. Share your thoughts and hidden tricks you are using in your day-to-day routine as comments. Enjoy.!!

Reference: http://www.howtogeek.com/235101/10-ways-to-open-the-command-prompt-in-windows-10/

Basically I need to know first where they are sitting in my system and once I know where they are and if I don't like that I put them somewhere else.

When we install modules globally in Node.JS it installs them at default location which is following in windows system:

${APPDATA}\npm

Which translates to

C:\Users\<Your-Username>\AppData\Roaming\npm

and I don't like Node.JS installing my global packages at this location and to change that you have to make change file "npmrc" which was at following location in my system:

D:\DiGiTSS\Programs\nodejs\node_modules\npm\

Open the file X:\<Your-Programs-Dir>\nodejs\node_modules\npm\npmrc, now you will see following line in this file:

prefix=${APPDATA}\npm

Now change this path to whatever you want, like I changed it to following as I wanted it to be static at some location:

prefix=D:\DiGiTSS\Programs\nodejs\global_modules

I like some of my programs to be installed on non-windows drive and so I choose different drive but generally I do not like development tools install something in Windows Roaming profile even if you install MySQL using installer it sets "data" directory default inside ProgramData in Windows which is following:

C:\ProgramData\MySQL\MySQL Server 5.x\Data\

I don't like this either, we will learn about how to change this in another post.

Looking forward to hear back from you if this tip helped and even if it did not.!

Error description:

Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'knight' defined in class path resource [com/digitss/knights/knight.xml]: BeanPostProcessor before instantiation of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.aop.aspectj.AspectJPointcutAdvisor#0': Cannot create inner bean '(inner bean)' of type [org.springframework.aop.aspectj.AspectJMethodBeforeAdvice] while setting constructor argument; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)': Cannot resolve reference to bean 'embark' while setting constructor argument; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'embark': Instantiation of bean failed; nested exception is java.lang.NoClassDefFoundError: org/aspectj/weaver/reflect/ReflectionWorld$ReflectionWorldException
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:454)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:295)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:223)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:292)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:626)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:932)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:479)
    at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
    at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)
    at com.springinaction.knights.KnightMain.main(KnightMain.java:13)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.aop.aspectj.AspectJPointcutAdvisor#0': Cannot create inner bean '(inner bean)' of type [org.springframework.aop.aspectj.AspectJMethodBeforeAdvice] while setting constructor argument; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)': Cannot resolve reference to bean 'embark' while setting constructor argument; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'embark': Instantiation of bean failed; nested exception is java.lang.NoClassDefFoundError: org/aspectj/weaver/reflect/ReflectionWorld$ReflectionWorldException
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveInnerBean(BeanDefinitionValueResolver.java:282)
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:126)
    at org.springframework.beans.factory.support.ConstructorResolver.resolveConstructorArguments(ConstructorResolver.java:629)
    at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:148)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1045)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:949)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:487)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:295)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:223)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:292)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:198)
    at org.springframework.aop.framework.autoproxy.BeanFactoryAdvisorRetrievalHelper.findAdvisorBeans(BeanFactoryAdvisorRetrievalHelper.java:86)
    at org.springframework.aop.framework.autoproxy.AbstractAdvisorAutoProxyCreator.findCandidateAdvisors(AbstractAdvisorAutoProxyCreator.java:101)
    at org.springframework.aop.aspectj.autoproxy.AspectJAwareAdvisorAutoProxyCreator.shouldSkip(AspectJAwareAdvisorAutoProxyCreator.java:103)
    at org.springframework.aop.framework.autoproxy.AbstractAutoProxyCreator.postProcessBeforeInstantiation(AbstractAutoProxyCreator.java:276)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInstantiation(AbstractAutowireCapableBeanFactory.java:890)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.resolveBeforeInstantiation(AbstractAutowireCapableBeanFactory.java:862)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:448)
    ... 10 more
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)': Cannot resolve reference to bean 'embark' while setting constructor argument; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'embark': Instantiation of bean failed; nested exception is java.lang.NoClassDefFoundError: org/aspectj/weaver/reflect/ReflectionWorld$ReflectionWorldException
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:329)
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:107)
    at org.springframework.beans.factory.support.ConstructorResolver.resolveConstructorArguments(ConstructorResolver.java:615)
    at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:148)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1045)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:949)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:487)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458)
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveInnerBean(BeanDefinitionValueResolver.java:271)
    ... 28 more
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'embark': Instantiation of bean failed; nested exception is java.lang.NoClassDefFoundError: org/aspectj/weaver/reflect/ReflectionWorld$ReflectionWorldException
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1007)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:953)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:487)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:314)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:323)
    ... 36 more
Caused by: java.lang.NoClassDefFoundError: org/aspectj/weaver/reflect/ReflectionWorld$ReflectionWorldException
    at java.lang.Class.getDeclaredConstructors0(Native Method)
    at java.lang.Class.privateGetDeclaredConstructors(Class.java:2671)
    at java.lang.Class.getConstructor0(Class.java:3075)
    at java.lang.Class.getDeclaredConstructor(Class.java:2178)
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:78)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1000)
    ... 42 more
Caused by: java.lang.ClassNotFoundException: org.aspectj.weaver.reflect.ReflectionWorld$ReflectionWorldException
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 48 more

To fix this either download AspectJ and add aspectjrt.jar and aspectjweaver.jar to your classpath or make following change in your pom.xml if you are using maven.

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>${spring-framework.version}</version>
        </dependency>
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.6.1</version>
        </dependency>

But yeah I was talking about "Remembering last page or position of the PDF file opened" and when I did some google today I just figured out that it is possible to do it in Windows too without using any new software but just with Adobe Acrobat Reader.

In your Acrobat Reader go to "Edit -> Preferences" (or press CTRL + K) and then navigate to "Documents" tab and check the check-box which says "Restore last view settings when reopening documents".

Restore last view settings when reopening documents

Bingo! Once you change this preference and reopen your Adobe Acrobat, it will remember last position and page of all your PDF documents or e-books. Enjoy!!

Moto G comes with decent specs for a entry level or budget smartphone and runs Android 4.4.4 (KitKat) quite well. Both Moto G and Moto G 2nd generation comes with same RAM and CPU and so upgrading to Lollipop will not make any difference in terms of performance between Moto G and Moto G 2nd Generation phones.

After upgrading you will for sure see a slow down in your performance and the biggest feature except bug-fixes and GUI enhancements you will see is multi-user support. So if you want to create another account for your kids to play games on your phone or for whatever reason multi-user support is important for you then you can make a compromise to slow down your phone a bit and get an Android Lollipop upgrade for your Moto G.

Yeah it has new and improved material design, improved notifications and improved run-time performance+battery life but all that is in vain if your phone hardware is incapable for the software.

Find out what Android Lollipop has to offer here. If you still want to try be safe by finding out how to revert back to stock OS before you upgrade.

Use autocomplete="off" for all the fields for which you want to turn off autocomplete. Certain browsers might just not comply or understand this tag at input level in that case you will have to disable them at form level as well. Some version of Chrome browser is observed to have such issues, but for other than exceptions for rest of the others you can simply specify autocomplete="off" like following example:

<!-- To disable autocomplete for specific input element --><form action="/forgotPassword/action" method="post"><input autocomplete="off" name="username" type="text" /><input name="ForgotPassword" type="submit" /></form>

or

<!-- To disable autocomplete for all input elements within the form --><form action="/forgotPassword/action" autocomplete="off" method="post"><input name="username" type="text" /><input name="ForgotPassword" type="submit" /></form>

While I am writing this, Chrome in my system is updated to version 39.x and it respects autocomplete="off" attribute without any problem. But at the same time Safari 8.0.2 in my Mac do not show suggestions even when I don't have this attribute specified. Both Firefox 34 and Chrome 39 respects autocomplete attribute at both form and element level, so you can apply it based on your need.

Xubuntu / Xfce on Ubuntu Server

I recently started using Ubuntu and I really liked the way things work in Ubuntu. I really like that when you setup Ubuntu Server distribution it does not come with GUI at all and that way it saves us from spending few mega-bytes of memory and we won't be wasting around 200MB behind graphical display and related processes, which we won't be using on the Server OS which usually does it's job without requiring us to install any GUI application on the Server.

But well many a time we may want to setup light weight x-window system on our Linux (Ubuntu) system and we can do that with setting up Xface or it's Ubuntu name as "Xubuntu".

To setup lightweight Xface or Xubuntu system on your Ubuntu Server setup you just need to follow some simple commands and that's it, you are done.

So if you are ready to setup, just follow some simple apt-get commands and install minimal packages required to setup lightweight GUI system on your Ubuntu Server:
# To get and install xfce4

$ sudo apt-get install xfce4

# Set of required packages for minimal setup

$ sudo aptitude install catfish elementary-icon-theme exo-utils flex gigolo gnome-icon-theme-full gnome-system-tools gnome-time-admin gthumb gthumb-data gtk2-engines-pixbuf indicator-application-gtk2 indicator-messages-gtk2 leafpad libclutter-1.0-0 libclutter-1.0-common libclutter-gtk-1.0-0 libcogl-common libcogl5 libconfig-inifiles-perl libencode-locale-perl libexo-1-0 libexo-common libfile-listing-perl libfont-afm-perl libgarcon-1-0 libgarcon-common libgdome2-0 libgdome2-cpp-smart0c2a libgegl-0.0-0 libglade2-0 libgnomevfs2-extra libgsf-1-114 libgsf-1-common libgstreamer-perl libgtk2-notify-perl libgtk2-trayicon-perl libhtml-form-perl libhtml-format-perl libhtml-parser-perl libhtml-tagset-perl libhtml-tree-perl libhttp-cookies-perl libhttp-daemon-perl libhttp-date-perl libhttp-message-perl libhttp-negotiate-perl libid3tag0 libido-0.1-0 libilmbase6 libio-socket-ssl-perl libjpeg-progs libkeybinder0 liblink-grammar4 libloudmouth1-0 liblwp-mediatypes-perl liblwp-protocol-https-perl libmad0 libmailtools-perl libnet-dbus-perl libnet-http-perl libnet-ssleay-perl liboobs-1-5 libopenexr6 libotr2 libots0 libsexy2 libthunarx-2-0 libtie-ixhash-perl libtimedate-perl libtumbler-1-0 liburi-perl libwww-perl libwww-robotrules-perl libxfce4ui-1-0 libxfce4util-bin libxfce4util-common libxfce4util4 libxfcegui4-4 libxfconf-0-2 libxml-parser-perl libxml-twig-perl libxml-xpath-perl libxss1 link-grammar-dictionaries-en m4 orage  python-configobj python-glade2 ristretto synaptic system-tools-backends tango-icon-theme tango-icon-theme-common thunar thunar-archive-plugin thunar-data thunar-media-tags-plugin thunar-volman ttf-droid ttf-lyx tumbler tumbler-common xfce-keyboard-shortcuts xfce4-appfinder xfce4-cpugraph-plugin xfce4-fsguard-plugin xfce4-indicator-plugin xfce4-mount-plugin xfce4-netload-plugin xfce4-notes xfce4-notes-plugin xfce4-notifyd xfce4-panel xfce4-places-plugin xfce4-power-manager xfce4-power-manager-data xfce4-quicklauncher-plugin xfce4-session xfce4-settings xfce4-systemload-plugin xfce4-taskmanager xfce4-terminal xfce4-utils xfce4-verve-plugin xfce4-volumed xfconf xfdesktop4 xfdesktop4-data xfwm4 xfwm4-themes xubuntu-artwork xubuntu-default-settings xubuntu-icon-theme xubuntu-wallpapers gnome-system-monitor

# You may want to install firefox

$ sudo apt-get install abrowser

# Remove screen-saver, as you do not want to waste cpu-cycles on your Server-OS

$ sudo apt-get remove xscreensaver xscreensaver-data

Once you are done with above setup, you will be having working Xfce / Xubuntu on top of your Ubuntu Server. You just need to reboot and you will see decent Xubuntu log-in screen. You might think that why do I need to install Xfce4 and then all packages manually? but the reason is we are installing here only bare-minimum things instead of installing all packages which come with Xubuntu. So above setup installs visual themes, some packages which help you to view files, directories, configure system / network etc.

If you want to install complete Xubuntu on top of your Ubuntu-Server you just need to type, one line:

$ sudo apt-get install xubuntu-desktop

but, this way you will end up installing all those packages including office, multimedia and many others which you may not want on your Server unless you're going to use this system as development machine.