Objective-c class, instance member, static variable, object method, class method (static method), object,

Objective-c class, instance member, static variable, object method, class method (static method), object,

First, the class

In iOS, the declaration of a class is separated from its implementation, that is, it cannot be written in the same file, the declaration is placed in the. h file, and the implementation is placed in the. m file. Introduce. h files in the implementation file, #import "Xxx.h"
Declare a class:
#import <Foundation/Foundation.h>
@interface Person:nsobject

@end

To implement a class:

#import "Person.h"
@implementation person

@end

Second, instance members

In the iOS class the bar variable is called the instance variable, and the default permission is protected, in the class can only declare the instance variable, must be able to declare the method. And you cannot declare static instance variables in. h files, which can only be declared and used in. M.
Eg:
#import <Foundation/Foundation.h>

@interface person:nsobject{
int age;
nsstring* name; A string in iOS
static int dwint; Error, can ' t
}
@end

Third, static member variables

Static instance variables cannot be declared in the. h file, and can only be declared and used in. M.
Eg:
#import "Person.h"
@implementation person

static int dwint=20;

@end

Iv. Object Methods

Object methods cannot be declared in parentheses, can only be declared outside of parentheses, and precede with-.
#import <Foundation/Foundation.h>

@interface person:nsobject{
int age;
nsstring* name; A string in iOS
}
-(int) getage;
-(nsstring*) getName;
-(void) Setage: (int) _age;
-(void) SetName: (nsstring*) _name;
-(void) Setage: (int) _age andname: (nsstring*) _name;
@end


Implement. M
#import "Person.h"

@implementation person
static int dwint=20;
-(int) getage{
return age;
}
-(nsstring*) getname{
return name;
}
-(void) Setage: (int) _age{
Age=_age;
}
-(void) SetName: (nsstring*) _name{
Name=_name;
}
-(void) Setage: (int) _age andname: (nsstring*) _name{
Age=_age;
Name=_name;
}
+ (int) getstatic{
return dwint;
}
@end

Five, class method

Class methods cannot be declared in parentheses, can only be declared outside of parentheses, and precede with +.
#import <Foundation/Foundation.h>

@interface person:nsobject{
int age;
nsstring* name; A string in iOS
}
-(int) getage;
-(nsstring*) getName;
-(void) Setage: (int) _age;
-(void) SetName: (nsstring*) _name;
-(void) Setage: (int) _age andname: (nsstring*) _name;
+ (int) getstatic;
@end

Implement. M

#import "Person.h"
@implementation person
static int dwint=20;
-(int) getage{
return age;
}
-(nsstring*) getname{
return name;
}
-(void) Setage: (int) _age{
Age=_age;
}
-(void) SetName: (nsstring*) _name{
Name=_name;
}