// 驗證手機號碼，中間用****代替
-  (NSString *)numberSuitScanf:(NSString*)number{

    NSMutableString *phoneStr = [NSMutableString stringWithString:number];

    NSString *regex = @"^((13[0-9])|(147)|(15[^4,\\D])|(18[0,5-9]))\\d{8}$";
    NSPredicate *pred = [NSPredicate predicateWithFormat:@"SELF MATCHES %@"
 
, regex];

    // 判斷當前字串是否為手機號
    BOOL isMatch = [pred evaluateWithObject:phoneStr];
    if (isMatch) {
        [phoneStr replaceCharactersInRange:NSMakeRange(3, 4) withString:@"****"];
    }

    return [NSString stringWithString:phoneStr];
}

一步做完，簡單實用