IPhone , Objective C Tutorial For Beginners

Working with Objects in Objective-C

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Constructing and Manipulating Paths with NSPathUtilities

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Files in objective C

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Files in objective C will be post, Sorry for inconvenience.

Directories in Objective-C

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Directories in Objective-C will be post, Sorry for inconvenience.

Dictionary objects in Objective C

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Dictionary objects in Objective C will be post, Sorry for inconvenience.

Array in Objective C

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Array in Objective C

Numbers in Objective C

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Numbers in Objective C

Strings in Objective C

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Using Strings in Objective C

As we know that String values are given in double quotes in java and other language .
For example "Welcome to IOS Tutorials".

But in objective c, it is different string value, we have to use "@" symbol to represent a string value before the quotes. Example is given below.
NSLog(@"Welcome to IOS Tutorials");

Creating String object

In Objective C, two types of string Objects are there one is mutable and Immutable.

For create the Immutable string we have to use NSString and to create mutable we have to use NSMutableString. If we are creating a string object using NSString, it is called immutable string object. It means this string can only assigned only once, that string cannot subsequently be modified in any way.
NSString *string1 = @"immutable String";

For Mutable string object, we use NSMutableString class. NSMutableString is a subclass of NSString.
It is different to assign a mutable string object.
for example
NSMutableString *string2 = [NSMutableString stringWithString:@" Mutable String "];
or
NSMutableString *string2 = [NSMutableString stringWithString: string1];// string1 is a NSString(immutable ).

Copying a Strings in Objective C

NSMutableString *str1;
NSMutableString *str2;
str1 = [NSMutableString stringWithString: @"This is a string"];
str2 = str1;
NSLog (@"string1 = %@", str1);
NSLog (@"string2 = %@", str2);

Finding a Substring

NSString *str1 = @"IOS tutorial generator";
NSRange range;
range = [str1 rangeOfString: @"tutorial generator"];
NSLog (@"found at index %lu", range.location);
NSLog (@"length = %lu", range.length);

Appending String

NSString *str1 = @"IOS tutorial generator";
NSMutableString *str2;
[str2 appendString: @" Tutorial for beginners"];

Replacing in String

NSMutableString *str1 = [NSMutableString stringWithString: @"IOS tutorial generator"];
[str1 replaceCharactersInRange: NSMakeRange(1, 4) withString: @"Objective C"];
NSLog (@"string1 = %@", string1);

Search and Replacing String

NSMutableString *str1 = [NSMutableString stringWithString: @"Objective C tutorial generator"];
[str1 replaceCharactersInRange: [string1 rangeOfString: @"Objective C"] withString: @"IOS"];

Deleting in String

NSMutableString *str1 = [NSMutableString stringWithString: @"Objective C tutorial generator"];
[str1 deleteCharactersInRange: [str1 rangeOfString: @"Objective C"]];

Return a word Subsection of a String

NSMutableString *st1 = [NSMutableString stringWithString: @"Objective C tutorial generator"];
NSString *st2;
str2 = [str1 substringWithRange: NSMakeRange (4, 5)];
NSLog (@"str2 = %@", string2);

NSMutableString *str1 = [NSMutableString stringWithString: @"Objective C tutorial generator"];
NSString *str2;
str2 = [str1 substringFromIndex: 4];

Inserting a string into a String

NSMutableString *str1 = [NSMutableString stringWithString: @"Objective C tutorial generator"];
[str1 insertString: @", IOS " atIndex: 12];

Comparing Strings

NSString *str1 = @"Hello";
NSString *str2 = @"HHello";
if ([string1 isEqualToString: string2])
NSLog (@"String are Equal");
else
NSLog (@"String are not Equal");

Find String Prefixes and Suffixes

NSString *str1 = @"Objective C tutorial generator";
BOOL val;
val = [str1 hasPrefix: @"Objective"];
if (val)
NSLog (@"Yes it has prefix as Objective");
val = [str1 hasSuffix: @"generator"];
if (val)
NSLog (@"Yes it has Suffix as generator");

Converting to Upper or Lower Case

NSString *str1 = @"Objective c tutorials for beginners";
NSString *str2;
string2 = [string1 capitalizedString];
Output: Objective C Tutorials For Beginners

lowercaseString

NSString *str1 = @"Objective c tutorials for beginners";
NSString *str2;
str2 = [str1 lowercaseString];
Output: objective c tutorials for beginners

uppercaseString

NSString *str1 = @"Objective c tutorials for beginners";
NSString *str2;
str2 = [str1 uppercaseStringg];
Output: OBJECTIVE C TUTORIALS FOR BEGINNERS

Converting Strings to Numbers

NSString *str1 = @"100";
int IntVal = [str1 intValue];
NSLog (@"%i", IntVal);

Convert String to double

NSString *str1 = @"100.1998";
double Doubleval = [str1 doubleValue];
NSLog (@"%f", Doubleval);

Convert String to float

NSString *str1 = @"10.1092";
float Floatval = [str1 floatValue];
NSLog (@"%f", Floatval);

Convert String to NSInteger

NSString *str1 = @"10";
NSInteger Integerval = [str1 integerValue];
NSLog (@"%li", Integerval);

Converting a String Object to ASCII

NSString *str1 = @"The quick browen fox";
const char *utfStringval = [str1 UTF8String];
printf ("Converted string = %s\n", utfStringval);

Polymorphism and Inheritance in Objective C

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Polymorphism

Polymorphism is the ability to have more than one form in brief, the methods with the same name in different classes.

see more on here to view examples .

Inheritance

We can also implement inheritance in Objective-C. Inheritance enables programmer to inherit methods and properties from other class, this is known as inheritance. In inheritance there are two types class Base Class and Sub Class. Base class is the class that all sub classes inherit so all the sub class have the property of base class.

Example

//Base Class

@interface A: NSObject

{

}

-(void) ab;

-(void)bc;

@end

@implementation A

-(void) ab

{

NSLog(@"at Method ab from class A");

}

-(void) bc

{

NSLog(@"at Method bc from class A");

}

@end

//Sub Class

@interface B: A

{

}

-(void) c;

-(void) d;

@end

@implementation B

-(void) c

{

NSLog(@"at Method c from class B");

}

-(void) d

{

NSLog(@"at Method d from class B");

}

@end

int main()

{

@autoreleasepool {

B *obj=[[B init] alloc];

[obj ab];

[obj bc];

[obj c];

[obj d];

[obj release];

}

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Control Statements and Loops in Objective C

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if else

if (condition) {

statement(s) execute statements if condition is true;

}

else

{

statement(s) execute statements if condition is not true;

}

Example

if(a==0)

NSLog(@"value of a=0");

else

NSLog(@"value of a!=0");

Else if

if(a==0)

NSLog(@"value of a=0");

else if(a==1)

NSLog(@"value of a=1");

else

NSLog(@"value of a!=0 or a!=1");

Switch Statement

switch (expression)

{

case match1:

statements

break;

case match2:

statements

break;

default:

statements

break;

}

for

for (counter; condition; update counter) {

statement(s) execute statements if condition is true;

}

Example

for (int i = 0; i < 10; i++)

{

NSLog(@"%d time loop executed",i);

}

Nested for loop

for (int i = 0; i < 100; i++)

{

NSLog( @"%i", i);

for (int j = 0; j < 10; j++)

{

NSLog ( @"%i", j);

}

for in

for (Type newVariable in expression ) {

statement(s);

}

for (existingVariable in expression) {

statement(s);

}

Example

for (int i = 0; i < [myArray count]; i++)

{

NSLog([myArray objectAtIndex:i]);

}

while

while (condition) {

statement(s) execute statements if condition is true;

}

Example

int i = 0;

while ( i < 10 )

{

i++;

}

do while

do {

statement(s) execute statements if condition is true;

} while (condition);

Example

int i ;

{

i++;

} while (i < 10)

Jump statements

return ;

it will stop execution and returns a value to the calling function.

break;

Go away from a loop.

continue;

This will skip the rest of the loop and go back to the next loop condition iteration.

exit();

This will terminates the program.

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Operators in Objective-C

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Operator	Use
+	Addition
-	Subtraction
*	Multiplication
/	Division
%	Modulo

Relational and Equality Operators

Operator	Use

Equal to

Not equal to

Greater than

Less than

Greater than or equal to

Less than or equal to

Logical Operators

Operator	Use

NOT

Logical AND

Logical OR

Compound Assignment Operators

Operator	Use

Addition

Subtraction

Multiplication

\/=

Division

\%=

Modulo

Bitwise AND

Bitwise Inclusive OR

Exclusive OR

<<=

Shift Left

>>=

Shift Right

Increment and Decrement Operators

Operator	Use

Addition

Subtraction

Multiplication

Division

Modulo

Bitwise AND

Bitwise Inclusive OR

Exclusive OR

<<=

Shift Left

>>=

Shift Right

Bitwise Operators

Operator	Use

Bitwise AND

Bitwise Inclusive OR

Exclusive OR

Unary complement (bit inversion)

Shift Left

Shift Right

The operators in objective c is similar to other languages only.

Data Types in Objective C

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Int Data Type

In Objective C int data type can store a positive or a negative number.

In a 32-bit PC, the maximum range of an unsigned int is 0 to 4294967295. On a 64-bit system the range is 0 to 18,446,744,073,709,551,615.

The case of signed int values, the ranges are −2,147,483,648 to +2,147,483,647 and −9,223,372,036,854,775,808 to +9,223,372,036,854,775,807 for 32-bit and 64-bit implementations respectively.

Int have 4 Bytes size.

int a=100;

Char Data Type

In Objective-C char data type is used to store a single character .For example a digit or punctuation mark or space character

Char have 1 Byte size

char a='a';

char b='+';

char c='1';

Float Data Type

We can use a variable declared to be of type float to store values containing decimal

places. To display a floating-point value, the NSLog conversion characters %f are
used.

Float have 4 bytes size

float f=3.14f;

Double Data Type

The type double is similar to the type float, but it is used whenever the range provided

by a float variable is not sufficient.Variables declared to be of type double can store

roughly twice as many significant digits as can a variable of type float. Most computers

represent double values using 64 bits.

Unless told otherwise, the Objective-C compiler considers all floating-point constants

to be double values.To explicitly express a float constant, append either f or F to the

end of the number, like so:

12.5f

To display a double value, you can use the format characters %f, %e, or %g, which are

the same format characters used to display a float value.

Double have 8 Bytes size

Basic Data Types

Type Constant Examples NSLog chars

char ’a’, ’\n’ %c

short int —   %hi, %hx, %ho

unsigned short   —   %hu, %hx, %ho

int 12, -97, 0xFFE0, 0177 %i, %x, %o

unsigned int 12u, 100U, 0XFFu %u, %x, %o

long int 12L, -2001, 0xffffL %li, %lx, %lo

unsigned long int 12UL, 100ul, 0xffeeUL %lu, %lx, %lo

long long int 0xe5e5e5e5LL, 500ll %lli, %llx, &llo

unsigned long long int 12ull, 0xffeeULL %llu, %llx, %llo

float 12.34f, 3.1e-5f,0x1.5p10, 0x1P-1   %f, %e, %g, %a

double 12.34, 3.1e-5, 0x.1p3 %f, %e, %g, %a

long double 12.341, 3.1e-5l %Lf, $Le, %Lg

id nil %p

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Outlets

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Outlets are Objective-C class properties. They are declared using the keyword IBOutlet. The declaring an outlet is done in your controller class header file, and might look something like this:

@property (nonatomic, retain) IBOutlet UIButton *myButton;
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Creating your first Iphone Project

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Open your Xcode from Application and select File ➤ New ➤ New Project. Select the Single View Application template, and then click Next. ,

Name the product name and class name.

choose the path to save your program

You wil get another window (See below), In that you can see the View Controller at the left side. The project navigator showing the class files that were created for us by the project template. Note that our class prefix was automatically incorporated into the class file names.

There we can see two .h file named "heloAppDelegate.h" and "HeloViewController.h".We have given "Helo" as our class name. Select the file "HeloViewController.h" (to implement interface section). Declare your methods and instance variable here.

Choose "HeloViewController.m" to implement your methods . You can see there is already some methods are defined .

On View Controller we can also see a .xib file . Here is we adding the UI tools into our application. There is two .xib file in view controller one is for IPhone and another for IPad click the "HeloViewController_iphone.xib" file will see the frame like below.

Now we have to add the UI controls . UI controls are there in right bottom called Object Library also we can choose it by menu from Select View ➤ Utilities ➤ Show Object Library .

Just drag the tools on the frame and change the title name or other properties from the Inspector pane(we will introduce you more about the inspector pane later).I added two textfield and a button and changed the title of Button to "Show" so the frame will be like below.

Now type the code in interface file

#import <UIKit/UIKit.h>

@interface txtViewController : UIViewController

{

UITextField *txt_first,*txt_second;

}

-(IBAction)toshow:(id)sender;

@end

Type the below code on Implementation file

-(IBAction)toshow:(id)sender

{

second.text=first.text;

first.text=@"";

}

Go to your xib file. You can see the cubes (it known as Files owner) displayed between Navigator area and Editor area, click the Files owner

When you click the files owner button in inspecter pane , it shows Connection inspector pane there we can see the variable txt_first, txt_second which we given as instance variable on interface section . Also the IBAction method will be there.

Just drag from the check button from the variable to the corresponded textfield. so the compiler can understand the that variable is represent for which UI control. we have to drag for all variable to the the corresponded UI control.

Now drag the method to the button

when you drag it you can see the below window ,select touch up inside.

Your first IOS program is done Now go and run.

Model-View-Controller Paradigm in Coco Touch

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Model-View-Controller (MVC) Paradigm is a very logical way to implement the code that makes up a GUI-based application. Now a days very few of object- oriented frameworks are using MVC model as Coco Touch.

There are three categories in MVC pattern.

Model: The classes that hold your application’s data.
View: Made up of the windows, controls, and other elements that the user can see and interact with.
Controller: The code that binds together the model and view. It contains the application logic that decides how to handle the user’s inputs.

IOS Tutorials: Check the New tab

2012-05-08T10:18:00.001-07:00

IOS Tutorials: Check the New tab: Check the New tab Menu Introducing ANDROID CODE+ An integrated digital code destination where users Edit and Comment all of their favori...

Check the New tab

2012-05-08T08:24:00.001-07:00

Check the New tab Menu

Introducing ANDROID CODE+ An integrated digital code destination where users Edit and Comment all of their favorite content in one place. It's the new destination for Android Developers!

Click here

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Compiling and Running Program in X-code

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Step 1: When you click on X-Code you can see the below window. You have to choose "Create a new Xcode projects" to write a Objective c Program.

Step 2: Next window is shown below. You can see, there are many options . Now we are create a simple objective c program .So we have to Mac OS X Application

Step 3:On left side we ca see IOS section Mac OS X , in Mac OS x section select Application and Choose Command Line Tool Click next button.

Step 4: Here we have to put a product name and press enter.

Step 5: Select the path ,that where we want save the program.

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Accessing Instance Variable & Parameter Passing in Objective C

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In interface section we can declare instance variable, this variable can be use any method in the Implementation section or program section.

For example

// interface section it is used to declare methods and instance veriable

@interface ABC: NSObeject

{

Int a=10, b=2;

}

-(int) Sum;................

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Classes, Objects, and Methods in Objective c

2012-05-06T12:00:00.000-07:00

As we know Objective-C Support classes and objects. Objective-C is entirely different from C++ it have a strict object model, unlike C++. For instance, in Objective-C, classes are objects and can be dynamically managed: it is possible to addclasses at run-time, create instances based on the name of the class, ask a class for its methods, and so on.

An example Program in Objective C........
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Using Xcode

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Xcode is the Apple's integrated development environment (IDE), it's a complete tool setfor building Mac OS X and iPhone OS applications. Have a powerful Xcode sourceeditor, graphical power it Have a User Interface editor, and many other features. Xcodecan help you find mistakes in syntax and logical, and events will Suggest fixes.
Xcode 4 features a single window, the workspace window Called, That holds MOST of the data you need...............
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Introduction to Objective C

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It is the basic language used to implement Mac software. If you're ok with Object Oriented concepts & C , this will make a lot of sense. If you were not good in C, you have to study the C programming language first.

In this chapter, we dive right in and show you how to write your first Objective-C program. You won’t work with objects just yet; that’s the topic of the next chapter. We want you to understand the steps involved in keying in a program and compiling and running it. We give special attention to this process both under Windows and on a Macintosh computer.

To begin, let’s pick a rather simple example: a program that displays the phrase “Welcome to IOS Tutorial” on your screen. Without further ado, Program shows an Objective- C program to accomplish this task:

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