#pragma mark 判斷身份證號是否合法
- (BOOL)judgeIdentityStringValid:(NSString *)identityString {
 if (identityString.length != 18) return NO;
 // 正則表達式判斷基本 身份證號是否滿足格式
 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];
 //如果通過該驗證，說明身份證格式正確，但準確性還需計算
 if(![identityStringPredicate evaluateWithObject:identityString]) return NO;
 //** 開始進行校驗 *//
 //將前17位加權因子保存在數組里
 NSArray *idCardWiArray = @[@"7", @"9", @"10", @"5", @"8", @"4", @"2", @"1", @"6", @"3", @"7", @"9", @"10", @"5", @"8", @"4", @"2"];
 //這是除以11后，可能產生的11位余數、驗證碼，也保存成數組
 NSArray *idCardYArray = @[@"1", @"0", @"10", @"9", @"8", @"7", @"6", @"5", @"4", @"3", @"2"];
 //用來保存前17位各自乖以加權因子后的總和
 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;
 }
 //計算出校驗碼所在數組的位置
 NSInteger idCardMod=idCardWiSum%11;
 //得到最后一位身份證號碼
 NSString *idCardLast= [identityString substringWithRange:NSMakeRange(17, 1)];
 //如果等于2，則說明校驗碼是10，身份證號碼最后一位應該是X
 if(idCardMod==2) {
 if(![idCardLast isEqualToString:@"X"]||[idCardLast isEqualToString:@"x"]) {
 return NO;
 }
 }else{
 //用計算出的驗證碼與最后一位身份證號碼匹配，如果一致，說明通過，否則是無效的身份證號碼
 if(![idCardLast isEqualToString: [idCardYArray objectAtIndex:idCardMod]]) {
 return NO;
 }
 }
 return YES;
}

#pragma mark 判斷銀行卡號是否合法
-(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;
}