#pragma mark 判断身份证号是否合法
- (BOOL)judgeIdentityStringValid:(NSString *)identityString {
 if (identityString.length != 18) return NO;
 // 正则表达式判断基本 身份证号是否满足格式
 NSString *regex2 = @"^(^[1-9]\\d{7}((0\\d)|(1[0-2]))(([0|1|2]\\d)|3[0-1])\\d{3}$)|(^[1-9]\\d{5}[1-9]\\d{3}((0\\d)|(1[0-2]))(([0|1|2]\\d)|3[0-1])((\\d{4})|\\d{3}[Xx])$)$";
 NSPredicate *identityStringPredicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",regex2];
 //如果通过该验证，说明身份证格式正确，但准确性还需计算
 if(![identityStringPredicate evaluateWithObject:identityString]) return NO;
 //** 开始进行校验 *//
 //将前17位加权因子保存在数组里
 NSArray *idCardWiArray = @[@"7", @"9", @"10", @"5", @"8", @"4", @"2", @"1", @"6", @"3", @"7", @"9", @"10", @"5", @"8", @"4", @"2"];
 //这是除以11后，可能产生的11位余数、验证码，也保存成数组
 NSArray *idCardYArray = @[@"1", @"0", @"10", @"9", @"8", @"7", @"6", @"5", @"4", @"3", @"2"];
 //用来保存前17位各自乖以加权因子后的总和
 NSInteger idCardWiSum = 0;
 for(int i = 0;i < 17;i++) {
  NSInteger subStrIndex = [[identityString substringWithRange:NSMakeRange(i, 1)] integerValue];
  NSInteger idCardWiIndex = [[idCardWiArray objectAtIndex:i] integerValue];
  idCardWiSum   += subStrIndex * idCardWiIndex;
 }
 //计算出校验码所在数组的位置
 NSInteger idCardMod=idCardWiSum%11;
 //得到最后一位身份证号码
 NSString *idCardLast= [identityString substringWithRange:NSMakeRange(17, 1)];
 //如果等于2，则说明校验码是10，身份证号码最后一位应该是X
 if(idCardMod==2) {
  if(![idCardLast isEqualToString:@"X"]||[idCardLast isEqualToString:@"x"]) {
   return NO;
  }
 }else{
  //用计算出的验证码与最后一位身份证号码匹配，如果一致，说明通过，否则是无效的身份证号码
  if(![idCardLast isEqualToString: [idCardYArray objectAtIndex:idCardMod]]) {
   return NO;
  }
 }
 return YES;
}

#pragma mark 判断银行卡号是否合法
-(BOOL)isBankCard:(NSString *)cardNumber{
 if(cardNumber.length==0){
  return NO;
 }
 NSString *digitsOnly = @"";
 char c;
 for (int i = 0; i < cardNumber.length; i++){
  c = [cardNumber characterAtIndex:i];
  if (isdigit(c)){
   digitsOnly =[digitsOnly stringByAppendingFormat:@"%c",c];
  }
 }
 int sum = 0;
 int digit = 0;
 int addend = 0;
 BOOL timesTwo = false;
 for (NSInteger i = digitsOnly.length - 1; i >= 0; i--){
  digit = [digitsOnly characterAtIndex:i] - '0';
  if (timesTwo){
   addend = digit * 2;
   if (addend > 9) {
    addend -= 9;
   }
  }
  else {
   addend = digit;
  }
  sum += addend;
  timesTwo = !timesTwo;
 }
 int modulus = sum % 10;
 return modulus == 0;
}