View difference between Paste ID: AjGR1edc and h0ZK8Vn5

 #include <iostream>
 #include <string>
 using namespace std;
 
 
 bool isValid(const string& cardNumber)
 {
 	if ((sumOfDoubleEvenPlace(cardNumber) + SumOfOddPlace(cardNumber)) % 10 != 0)
 	{
 		return false;
 	}
 
 /* Test for startsWith? */
 /* test for length */
 
 }
 bool startsWith(const string& cardNumber, const string& substr)
 {
 	if (cardNumber[0] - '0' == 4 || cardNumber[0] - '0' == 5 || cardNumber[0] - '0' == 6 ||
 		(cardNumber[0] - '0' == 3 && cardNumber[1] - '0' == 7))
 /* Then do what? */
 
 }
 
 
 
 
 
 
 
 
 
 //-----------------------------------------------------------------------------------------------------------
 int getDigit(int number)
-	if ((cardNumber[number] - '0') * 2 >= 10)
+
 	if ((cardNumber[number] - '0') * 2 >= 10)// Where is it getting cardNumber from? You didn't pass cardNumber in above
 	{
 		int A = (cardNumber[number] - '0') * 2 - 10;
 		int B = ((cardNumber[number] - '0') * 2) / 10;
 		number = A + B;
 		return number;
 	}
 	else
 	{
 		number = cardNumber[number] - '0';
 		return number;
 	}
 }
 int sumOfDoubleEvenPlace(const string& cardNumber)
 {
 	int Even = 0;
 	int number = 0;
 	while (number < cardNumber.length())
 	{
 		if (number == 0 || number % 2 == 0)
 		{
 			Even = Even + getDigit(number);
 		}
 
 		number++;
 	}
 	return cardNumber = Even;
 }
 int SumOfOddPlace(const string& cardNumber)
 {
 	int Odd = 0;
 	int number = 1;
 	while (number < cardNumber.length())
 	{
 		if (number == 1 || number % 2 != 0)
 		{
 			Odd = Odd + getDigit(number);
 		}
 		number++;
 	}
 	return cardNumber = Odd;
 }
 int main()
 {
 	cout << " Enter a credit card # :";
 	string cardNumber;
 	getline(cin, cardNumber);
 
 	if (isValid(cardNumber))
 	{
 		cout << cardNumber << " is a valid number \n";
 	}
 
 	else
 	{
 		cout << cardNumber << " is not a valid number \n";
 	}
 
 	return 0;
 
 }