NSString、NSMutableString的内存地址类型

    NSString *a1 = [[NSString alloc] initWithFormat:@"stringTestTwo"];     __weak NSString *a2 = a1;     NSLog(@"a1:%@", a1);     NSLog(@"a2:%@", a2);     a1 = nil;     NSLog(@"a1:%@", a1);     NSLog(

>>阅读原文<<