简单的数组随机打乱顺序

  //打乱顺序
    NSArray *tArr = [@"1", @"2", @"3", @"4", @"5", @"6", @"7", @"8"];

    tArr = [tArr sortedArrayUsingComparator:^NSComparisonResult(NSString *obj1, NSString *obj2) {
        int seed = arc4random_uniform(2);
        if (seed) {
            return NSOrderedAscending;
        } else {
            return NSOrderedDescending;
        }
    }];