Objective-C:在循环中从NSString中删除尾随逗号

Question

在我的介绍性Objc课程中,这是一个简单的挑战,这让我感到非常悲痛.我已经尝试了一些我在X-code API中选择的东西试图解决这个问题,但我没有运气.挑战规范包括限制:我不能更改for循环之外的任何代码,我的输出不能包含尾随逗号.它目前的迭代确实如此,我不知道如何摆脱它!

以下是当前形式的代码:

    NSString *outputString = @"";
    int loopMaximum = 10;

    for (int counter = 1; counter <= loopMaximum; counter++) {
        outputString = [NSString stringWithFormat:@"%@ %d,", outputString, counter];
        //Not sure how to get rid of trailing comma =/
    }

    NSLog(@"%@", outputString);

Answer 1

更好的方法是这样的:

NSMutableString *outputString = [NSMutableString string];
int loopMaximum = 10;

for (int counter = 1; counter <= loopMaximum; counter++) {
    if (counter > 1) {
        [outputString appendString:@", "];
    }
    [outputString appendFormat:@"%d", counter];
}

NSLog(@"%@", outputString);