Objective-C in my eyes

From the first applicationProgramStart with helloworld:

Objective-C version:

 # Import  <  Foundation  /  Foundation. h  >  

  Int  Main (  Int  Argc,  Const     Char    *  Argv []) {
NSAID utoreleasepool  *  Pool  =  [[NSAID utoreleasepool alloc] init];

  //  Insert code here...  
  Nslog (  @"  Hello, world!  "  );
[Pool drain];
  Return    0  ;
} 

# Import <Foundation/Foundation. h> indicates to import or include information about the system file Foundation. H into a program.

Int main (INT argc, const char * argv [])

This function is a special function used to accurately indicate where the program will start execution. This function returns the int type.

NSAID utoreleasepool*Pool=[[NSAID utoreleasepool alloc] init];

This statement reserves the memory space for the automatically released pool.
Nslog is a function in the objective-C library.
[Pool drain] releases the allocated memory pool.

C # version of the hello World Program:

UsingSystem;
NamespaceFirstapp
{
ClassProgram
{
Static VoidMain (String[] ARGs)
{
Console. writeline ("Hello World");
}
}
}
 

Let's take a look at a complete console application:

Objective-C version:

 # Import  < Foundation  /  Foundation. h  >  

@ Interface fraction: nsobject
{
  Int  Numerator;
}

  -  (  Void  ) Print;
  -  (  Void  ) Setnumerator :(  Int ) N;

@ End

@ Implementation Fraction

  -  (  Void  ) Print
{
Nslog (  @"  % I  "  , Numerator );
}
  -  (  Void  ) Setnumerator :(  Int  ) N
{
Numerator  = N;
}

@ End

  Int  Main (  Int  Argc,  Const     Char     *  Argv []) {
NSAID utoreleasepool  *  Pool  =  [[NSAID utoreleasepool alloc] init];

Fraction  * Fraction  =  [Fraction alloc];
Fraction  =  [Fraction init];

[Fraction setnumerator:  10  ];

Nslog (  @"  The value of numerator is:  "  );
[Fraction print];

[Fraction release];
[Pool drain];
  Return     0 ;
} 

We willCodeTranslate to C #:

 Using  System;

  Namespace  Firstapp
{
  Public     Class  Fraction: Object
{
  Private     Int  Numerator;
  Public    Void  Setnumberator (  Int  N)
{
Numerator  =  N;
}
  Public     Void  Print ()
{
System. Console. writeline (numerator );
}

}
  Class  Program
{
  Static     Int Main (  String  [] ARGs)
{
Fraction  =     New  Fraction ();
Fraction. setnumberator (  10  );
Console. writeline (  @"  The value of numerator is:  "  );
Fraction. Print ();
  Return    0  ;
}
}
} 

In objective-C, the base class of all classes is nsobject, while in C #, the base class is object.

In objective-C,

@ Interface Fraction

@ End

@ Interface is used to describe classes, data members of classes, and methods of classes.

In C #, it indicates:

Class fraction {

}

In objective-C,

@ Implementation is used to implement the methods of classes defined in @ interface.

In objective-C,

IntNumerator; here, numerator is an instance variable, defined in {} after the class name.

-(Void) Print; the class method print is defined here, which indicates the class instance method.

If you define+(Void) Print; indicates the class method.

In C,

Static void print (){

}

Indicates the class method.

In objective-C,

-(Void) Setnumerator :(Int) N is the parameter of the setnumerator method, which is of the int type.

In C,

Void setnumerator (int n ){

} 

In objective-C,

-(Void) Setto :(Int) N over :(Int) D;

N and D are parameters. This is a multi-parameter function.

There is also a representation:

-(Void)Set:(Int) N :(Int) D {
Numerator=N; numerator1=D;
}

In C,

Void setto (int n, int d ){

}

 

In objective-C,

@ PropertyIntNumerator1;

@ Synthesize numerator1;

Is the abbreviated form of an attribute.

In C #, it is equivalent:

Public int numerator1 {Get; set ;}

A complete simple example of objective-C object-oriented:

 # Import  <  Foundation  /  Foundation. h  > 

@ Interface fraction: nsobject
{
  Int  Numerator;
}



  -  (  Void  ) Print;


  -  (  Void  ) Setnumerator :(  Int  ) N;
  -  (  Int ) Numerator;
  -  (  Void  ) Setto :(  Int  ) N over :(  Int  ) D;

@ Property  Int  Numerator1;


@ End

@ Implementation Fraction

  -  (  Void  ) Print
{
Nslog (  @" % I  "  , Numerator );
}

  -  (  Void  ) Setnumerator :(  Int  ) N
{
Numerator  =  N;
}

  -  (  Int  ) Numerator
{
  Return Numerator;
}

@ Synthesize numerator1;

  -  (  Void  ) Setto :(  Int  ) N over :(  Int  ) D {
Numerator  =  N; numerator1  =  D;
}

  -  (  Void )  Set  :(  Int  ) N :(  Int  ) D {
Numerator  =  N; numerator1  =  D;
}

@ End

  Int  Main (  Int  Argc,  Const    Char     *  Argv []) {
NSAID utoreleasepool  *  Pool  =  [[NSAID utoreleasepool alloc] init];

Fraction  *  Fraction  =  [Fraction alloc];
Fraction  =  [Fraction init];

[Fraction setnumerator:  100 ];
[Fraction setnumerator1:  99  ];


Nslog (  @"  The value of numerator is:  "  );
[Fraction print];

Nslog (  @"  The value of numerator is: % I  "  , [Fraction numerator]);

Nslog (  @"  The value of numerators is: % I  " , [Fraction numerator1]);

[Fraction setto:  8  Over:  9  ];

Nslog (  @"  The value of numerators is: % I, % I  "  , [Fraction numerator], [fraction numerator1]);

[Fraction  Set  :  2  :  3  ];

Nslog ( @"  The value of numerators is: % I, % I  "  , [Fraction numerator], [fraction numerator1]);


[Fraction release];
[Pool drain];
  Return     0  ;
}