Objective—C_java中一个类有几个父类

1 [NSFileManager replaceItemAtURL:
2     withItemAtURL:
3     backupItemName:
4     options:
5     resultingItemURL:
6     error：
7 ];

[myObject someMethord:[anotherObject anotherMethord]];

Class *myObj = [[Class alloc] init];
Person *fred = [[Person alloc] init];
Dog *fido = [[Dog alloc] init];
Customer *acmeCorp = [[Customer alloc] init];
NSAutoReleasePool *pool = [[NSAutoReleasePool alloc] init];

-(int) addNumberz: (int) a　 toNumber: (int) b;

或者：

-(BOOL) sendEmailTo:(NSString *)paramTo
        withSubject:(NSString *)paramSubject
    andEmailMessage:(NSString *)paramEmailMessage{
// Send the email and return an appropriate value

   if([paramTo length]==0 || [paramSubject length]==0 || [paramEmailMessage]==0){
      //one or some of the parameters are empty
      NSLog(@"Empty parameter is/are provided.");
      return NO;
      }
   return YES;
}

[self   sendEmailTo:@"someone@somewhere.com"
        withSubject:@"My Subject"
    andEmailMessage:@"Please read my email."];

//this is AppDelegate.m file

#import "AppDelegate.h"
#import "MyClass.h"

@implementation AppDelegate
@synthesize window = _window;
-(BOOL)  　　　　　　　 application:(UIApplication *)application
　　 didFinishLaunchingWithOption:(NSDictionary *)launchOptions{
    
　　 MyClass *instance1 = [MyClass allocAndInit];
    NSLog(@"Instance 1 = %@", instance1);
    
   self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
　　self.window.backgroundColor = [UIColor whiteColor];
　　[self.window makeKeyAndVisible];
　　return YES;
}

1 #import <Foundation/Foundation.h>
2 
3 @interface MyClass : NSObject
4 
5 -(void) performAction: (int) param;
6 -(int) addNumber: (int) a toNumber: (int) b;
7 
8 @end

 1 #import "MyClass.h"
 2 
 3 @implementation MyClass
 4 
 5 -(void)performAction:(int)param{
 6     NSLog(@"You passed in the value %i", param);
 7 }
 8 
 9 -(int)addNumber:(int)a toNumber:(int)b{
10     return a+b;
11 }
12 
13 @end

 1 @interface Player : NSObject
 2 {
 3     //instance variables
 4     int score;  //所有需要定义的变量写在｛｝里
 5 }
 6 
 7 -(int) score;    //getter
 8 -(void) setScore: (int) amount;    //setter
 9 
10 @end

 1 @implementation Player
 2 // accessor methord
 3 -(int) score{
 4        return score;
 5 }
 6 
 7 -(void) setScore : (int) amount{
 8     score = amount;      
 9 }
10 
11 @end

 1 @interface Player : NSObject
 2 {
 3     //instance variables
 4     int score;  //所有需要定义的变量写在｛｝里
 5 }
 6 @property int score;　　//同样type和name的property会自动wrap上面的score 7 
 8 @end

 1 @implementation Player
 2 @synthesize score;
 3 
 4  
 5 @end

 1 @interface Player : NSObject2 @property int score;　　3 
 4 @end

 1 @implementation Player
 2
 3 @end

 1 @interface Player : NSObject
 2 
 3 //各种property的声明，property可以带自己的属性
 4 @property int score;　　
 5 @property (strong) NSString * firstName
 6 ...
 7 
 8 //各种方法的声明
 9 //methords
10 ...
11 
12 @end

 1 @implementation Player
 2 ｛
 3      //各种内部var的定义
 4      int year;
 5      float speed;
 6      ....
 7 }
 8 
 9 //各种方法的具体实现
10 //-methord
11 
12 @end

＃import "MyClass.h"

@implementation MyClass

- (id)init  //代表可以返回任何object
{
    self = [super init];  //self相当于this，本object自己，super代表NSObject，调用其init方法
    if (self) {
        <#initializations#>  //如果self存在则这里就是我们需要custom的init代码段
　　　　　score ＝ 5000；
    }
    return self;
}

@end

＃import <Foundation/Foundation.h>

@interface Player : NSObject

@property int score;

@end

＃import <Foundation/Foundation.h>   //调用apple的API就<>
#import "Player.h"    //调用本项目里的文件就""

int main(int argc, const char * argv[]){
  @autoreleasepool{
     //insert code here...
    Player * p = [[Player alloc] init];
    NSLog(@"The score is %i", p.score)  
  }
  return 0;
}

＃import "MyClass.h"

@implementation MyClass

- (id)initWithInt : (int) s  //NSObject里没有我们这个custom的init名字，所以我们要在.h里声明
{
    self = [super init];  //self相当于this，本object自己，super代表NSObject，调用其init方法
    if (self) {
        <#initializations#>  //如果self存在则这里就是我们需要custom的init代码段
　　　　　score ＝ s；
    }
    returnself;
}

- (id)init  //因为这时默认NSObject的init方法，所以.h里不用声明
{
    self = [super init];  //self相当于this，本object自己，super代表NSObject，调用其init方法
    if (self) {
        <#initializations#>  //如果self存在则这里就是我们需要custom的init代码段
　　　　　score ＝ 5000；
    }
    return self;
}

} @end

＃import <Foundation/Foundation.h>

@interface Player : NSObject
- (id)initWithInt : (int) s　　//我们需要做这一步，因为我们initWithInt在别的file里调用的时候是可见的

@property int score;

@end

＃import <Foundation/Foundation.h>   //调用apple的API就<>
#import "Player.h"    //调用本项目里的文件就""

int main(int argc, const char * argv[]){
  @autoreleasepool{
     //insert code here...
    Player * p = [[Player alloc] init];
    NSLog(@"The score is %i", p.score);
　　 Player *x = [[Player alloc] initWithInt: 7500];
　　 NSLog(@"The Scroe value is %i", [x score]);　　//换成x.score也可以 
 
  }
  return 0;
}

＃import "MyClass.h"

@implementation MyClass

- (id)initWithInt : (int) s  //NSObject里没有我们这个custom的init名字，所以我们要在.h里声明
{
    self = [super init];  //self相当于this，本object自己，super代表NSObject，调用其init方法
    if (self) {
        <#initializations#>  //如果self存在则这里就是我们需要custom的init代码段
　　　　　score ＝ s；
    }
    returnself;
}

- (id)init  //因为这时默认NSObject的init方法，所以.h里不用声明
{
    return [self initWithInt:5000];
}

} @end