字符串中的retain与copy

来源：互联网发布：广电网络电视怎么开编辑：程序博客网时间：2024/04/28 16:20

NSMutableString *mStr = [NSMutableStringstring];

[mStr setString:@"我没变"];

self.retainStr = mStr;

self.cpStr = mStr;

self.retainMStr = mStr;

self.cpMStr = mStr;

NSLog(@"retainStr:%@", self.retainStr);

NSLog(@"copyStr:%@", self.cpStr);

NSLog(@"retainMStr:%@",self.retainMStr);

NSLog(@"copyMStr:%@", self.cpMStr);

NSLog(@"\n");

[mStr setString:@"我变了"];

NSLog(@"retainStr:%@", self.retainStr);

NSLog(@"copyStr:%@", self.cpStr);

NSLog(@"retainMStr:%@",self.retainMStr);

NSLog(@"copyMStr:%@", self.cpMStr);

NSLog(@"\n");

NSString *str =@"我来了";//[[NSString alloc] initWithFormat:@"我来了"];//两种方式都一样。

self.retainStr = str;

self.cpStr = str;

self.retainMStr = [strmutableCopy];

self.cpMStr = [strmutableCopy];

NSLog(@"retainStr:%@", self.retainStr);

NSLog(@"copyStr:%@", self.cpStr);

NSLog(@"retainMStr:%@",self.retainMStr);

NSLog(@"copyMStr:%@", self.cpMStr);

NSLog(@"\n");

str =@"我走了";//[[NSStringalloc] initWithFormat:@"我走了"];//两种方式都一样

NSLog(@"retainStr:%@", self.retainStr);

NSLog(@"copyStr:%@", self.cpStr);

NSLog(@"retainMStr:%@",self.retainMStr);

NSLog(@"copyMStr:%@", self.cpMStr);

NSLog(@"\n");

结果：

2016-04-07 17:39:00.780 FMDBTest[1305:504297] retainStr:我没变

2016-04-07 17:39:00.780 FMDBTest[1305:504297] copyStr:我没变

2016-04-07 17:39:00.780 FMDBTest[1305:504297] retainMStr:我没变

2016-04-07 17:39:00.780 FMDBTest[1305:504297] copyMStr:我没变

2016-04-07 17:39:00.780 FMDBTest[1305:504297]

2016-04-07 17:39:00.780 FMDBTest[1305:504297] retainStr:我变了

2016-04-07 17:39:00.780 FMDBTest[1305:504297] copyStr:我没变

2016-04-07 17:39:00.781 FMDBTest[1305:504297] retainMStr:我变了

2016-04-07 17:39:00.781 FMDBTest[1305:504297] copyMStr:我没变

2016-04-07 17:39:00.781 FMDBTest[1305:504297]

2016-04-07 17:39:00.781 FMDBTest[1305:504297] retainStr:我来了

2016-04-07 17:39:00.781 FMDBTest[1305:504297] copyStr:我来了

2016-04-07 17:39:00.781 FMDBTest[1305:504297] retainMStr:我来了

2016-04-07 17:39:00.781 FMDBTest[1305:504297] copyMStr:我来了

2016-04-07 17:39:00.781 FMDBTest[1305:504297]

2016-04-07 17:39:00.781 FMDBTest[1305:504297] retainStr:我来了

2016-04-07 17:39:00.781 FMDBTest[1305:504297] copyStr:我来了

2016-04-07 17:39:00.781 FMDBTest[1305:504297] retainMStr:我来了

2016-04-07 17:39:00.781 FMDBTest[1305:504297] copyMStr:我来了

2016-04-07 17:39:00.782 FMDBTest[1305:504297]

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