将400电话中间加上-线

代码：

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.

    NSLog(@"--iphone--%@",[self getNewPhoneStr1:@"18502368888"]);

}
//只需传一个电话进去，可以返回一个处理好的加了-线的400电话字符串，如传4001234567，返回400-123-4567
- (NSString *)getNewPhoneStr1:(NSString *)phonestr
{
    if ([phonestr rangeOfString:@"-"].length == 0 && phonestr.length > 6) {
        NSMutableString *phoneNumber = [NSMutableString string];
        NSString *subStr = [phonestr substringToIndex:3];
        [phoneNumber appendFormat:@"%@-",subStr];
        subStr = [phonestr substringWithRange:NSMakeRange(3, 3)];
        [phoneNumber appendFormat:@"%@-",subStr];
        subStr = [phonestr substringWithRange:NSMakeRange(6, phonestr.length-6)];
        [phoneNumber appendString:subStr];

        phonestr = phoneNumber;
    }

    return phonestr;
}

输出：

2014-12-02 17:14:26.807 将400电话中间加上-线[21611:60b] --iphone--185-023-68888