OC——继承

继承的其中一个很重要的目的是为了实现多态。我们现在先来看看OC的继承。

一、继承

父类：

头文件

 1 //
 2 //  Peason.h
 3 //  01-继承和多态
 4 //
 5 //  Created by zhangjing on 15/7/5.
 6 //  Copyright (c) 2015年 zhangjing. All rights reserved.
 7 //
 8 
 9 #import <Foundation/Foundation.h>
10 
11 @interface Peason : NSObject
12 @property NSString *name;
13 @property int age;
14 
15 -(id)initWithName:(NSString*)name Age:(int)age;
16 -(void)Say;
17 @end

实现文件：

 1 //
 2 //  Peason.m
 3 //  01-继承和多态
 4 //
 5 //  Created by zhangjing on 15/7/5.
 6 //  Copyright (c) 2015年 zhangjing. All rights reserved.
 7 //
 8 
 9 #import "Peason.h"
10 
11 @implementation Peason
12 @synthesize name=_name;
13 @synthesize age=_age;
14 -(id)initWithName:(NSString*)name Age:(int)age
15 {
16     Peason* p=[[Peason alloc]init];
17     p.name=name;
18     p.age=age;
19     return p;
20 }
21 -(void)Say
22 {
23     NSLog(@"%@_____%@",self,self.name);
24 }
25 @end

子类：

头文件

 1 //
 2 //  Student.h
 3 //  01-继承和多态
 4 //
 5 //  Created by zhangjing on 15/7/5.
 6 //  Copyright (c) 2015年 zhangjing. All rights reserved.
 7 //
 8 
 9 #import "Peason.h"
10 
11 @interface Student : Peason
12 -(id)initWithName:(NSString*)name Age:(int)age;
13 -(void)Say;
14 @end

实现文件

 1 //
 2 //  Student.m
 3 //  01-继承和多态
 4 //
 5 //  Created by zhangjing on 15/7/5.
 6 //  Copyright (c) 2015年 zhangjing. All rights reserved.
 7 //
 8 
 9 #import "Student.h"
10 
11 @implementation Student
12 -(void)Say
13 {
14     NSLog(@"My name is %@. I am student.",self.name);
15 }
16 -(id)initWithName:(NSString*)name Age:(int)age
17 {
18     Student* s=[[Student alloc]init];
19     s.name=name;
20     s.age=age;
21     return s;
22 }
23 @end

调用函数

 1 //
 2 //  main.m
 3 //  01-继承和多态
 4 //
 5 //  Created by zhangjing on 15/7/5.
 6 //  Copyright (c) 2015年 zhangjing. All rights reserved.
 7 //
 8 
 9 #import <Foundation/Foundation.h>
10 #import "Peason.h"
11 #import "Student.h"
12 
13 int main(int argc, const char * argv[]) {
14     @autoreleasepool {
15         Peason* p=[[Peason alloc]initWithName:@"Tom" Age:14];
16         [p Say];
17         Student* s=[[Student alloc]initWithName:@"Jack" Age:12];
18         [s Say];
19     }
20     return 0;
21 }

输出结果：

2015-07-05 15:32:51.221 01-继承和多态[1281:44755] <Peason: 0x100206a30>_____Tom

2015-07-05 15:32:51.222 01-继承和多态[1281:44755] My name is Jack. I am student.

注意：如果子类想用和父类一样的初始化方法那么需要重新写一遍，如果不重写直接使用父类的初始化方法，那么得到的是一个父类的对象

posted @ 2015-07-05 15:34  zhangjing022  阅读(162)  评论(0)  编辑  收藏  举报