如何在 Objective-C 中反转 NSArray? [英] How can I reverse a NSArray in Objective-C?

问题描述

我需要反转我的 NSArray.

举个例子:

[1,2,3,4,5] 必须变成:[5,4,3,2,1]

实现这一目标的最佳方法是什么?

What is the best way to achieve this?

推荐答案

要获取数组的反向副本，请查看 danielpunkass'解决方案使用reverseObjectEnumerator.

For obtaining a reversed copy of an array, look at danielpunkass' solution using reverseObjectEnumerator.

要反转可变数组，您可以在代码中添加以下类别:

For reversing a mutable array, you can add the following category to your code:

@implementation NSMutableArray (Reverse)

- (void)reverse {
    if ([self count] <= 1)
        return;
    NSUInteger i = 0;
    NSUInteger j = [self count] - 1;
    while (i < j) {
        [self exchangeObjectAtIndex:i
                  withObjectAtIndex:j];

        i++;
        j--;
    }
}

@end

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