摘要：
有三个NSString， NSString *str1 = @"123"; NSString *str2 = [NSString stringWithFormat:@"123"]; NSMutableString *str3 = [NSMutableStringstringWithFormat:@"123"]; NSLog(@"str1 = %p , str2 = %p, str3 = %p", str1, str2, str3); NSLog(@"str1 = %d , str2 = %d, str3 阅读全文
