1. #import <Foundation/Foundation.h>
   
2. #import "NSStringTest.h"
   
3. int main(int argc, const char * argv[])
   
4. {
   
5.     NSMutableString *muStr = [NSMutableString stringWithFormat:@"abc"];
   
6.     NSStringTest * test = [[NSStringTest alloc]init];
   
7.     test.cStr = muStr;
   
8.     test.retainStr = muStr;
   
9.     test.strongStr = muStr;
   
10. [muStr appendFormat:@"123"];
    
11.     NSLog(@"muStr %@ %p",muStr,muStr);
    
12.     NSLog(@"copy %@ %p",test.cStr,test.cStr);
    
13.     NSLog(@"strong %@ %p",test.strongStr,test.strongStr);
    
14.     NSLog(@"retain %@ %p",test.retainStr,test.retainStr);
    
15.     return 0;
    
16. }

复制代码

1. #import <Foundation/Foundation.h>
   
2. 
   
3. @interface NSStringTest : NSObject
   
4. @property(nonatomic,copy)NSString* cStr;
   
5. @property(nonatomic,strong)NSString* strongStr;
   
6. @property(nonatomic,retain)NSString* retainStr;
   
7. @end

复制代码

执行结果：

2015-01-15 20:47:22.715 内存控制练习[2353:162418] muStr abc123 0x100204bf0

2015-01-15 20:47:22.716 内存控制练习[2353:162418] copy abc 0x100204eb0

2015-01-15 20:47:22.716 内存控制练习[2353:162418] strong abc123 0x100204bf0

2015-01-15 20:47:22.716 内存控制练习[2353:162418] retain abc123 0x100204bf0

Program ended with exit code: 0

从结果可以看出，copy是深复制，retain和strong是浅复制

干的漂亮

很好，学习了！！