- (void)viewDidLoad

{

    [super viewDidLoad];

    // Do any additional setup after loading the view.

    NSString *str = @"你好啊";

    NSMutableArray *arr = [[NSMutableArray alloc] init];

    for (int i = 0; i<str.length ; i++) {

        NSString *str1 = [str substringWithRange:NSMakeRange(i, 1)];

        NSString *str2 = [str1 stringByAppendingString:@"\n"];

        [arr addObject:str2];

    }

    NSString *str3;

    for (int i = 0; i<arr.count - 1; i++) {

        if (i == 0) {

            str3 = [arr[i] stringByAppendingString:arr[i+1]];

        }else{

            str3 = [str3 stringByAppendingString:arr[i+1]];

        }

    }

    NSLog(@"%@",str3);

}

2015-10-20 14:25:43.161 竖排文字[8130:197228] 你

好