iOS - 字符串倒序输出

• 核心算法：【只对英文字母数字有效】

   NSString *str = @"hello,world";
    NSMutableArray *array = [NSMutableArray array];
    for (int i=0; i<str.length; i++) {
        char charStr =  [str characterAtIndex:i];
        NSString *temStr = [NSString stringWithFormat:@"%c",charStr];
        [array addObject:temStr];
    }
    NSArray *reverseArray = [[array reverseObjectEnumerator] allObjects];
    NSString *reverseStr = [reverseArray componentsJoinedByString:@""];
    NSLog(@"%@",reverseStr);

• 核心技术点 数组倒序输出