一，代码。

- (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);
    
}

 

二，输出。

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