-stringByAppendingString:不起作用

Question

我需要连接两个NSStrings,我编写了下面的代码:

NSString *reverseResult = [[NSString alloc] initWithFormat:@""];
NSString *zero = [[NSString alloc] initWithFormat:@"0"];
NSString *one = [[NSString alloc] initWithFormat:@"1"];
int modRes;
while (num != 0) {
    modRes = num;
    modRes = num % 2;
    if (modRes == 0)
        [reverseResult stringByAppendingString:zero];
    else
        [reverseResult stringByAppendingString:one];
    num = num / 2;
}

当我调试代码时,我看到"stringByAppendingString"没有做我需要的东西(reverseResult保持@"",即使它到达那一行).

代码有问题吗？

Answer 1

stringByAppendingString返回一个新字符串,它不会修改现有字符串.您必须将结果存储在变量中.