credit_card_number

Sprint-3/revise/implement/card-validator.md

@@ -11,19 +11,19 @@ Here are the rules for a valid number:
 
 For example, the following credit card numbers are valid:
 
-```markdown
+markdown
 9999777788880000
 6666666666661666
-```
+
 
 And the following credit card numbers are invalid:
 
-```markdown
+markdown
 a92332119c011112 (invalid characters)
 4444444444444444 (only one type of number)
 1111111111111110 (sum less than 16)
 6666666666666661 (odd final number)
-```
+
 
 These are the requirements your project needs to fulfill:
 

Sprint-3/revise/implement/creditCardValidator.js

@@ -0,0 +1,30 @@
+function validateCreditCard(cardNumber) {
+    if (typeof cardNumber !== 'string' || cardNumber.length !== 16 || !/^\d{16}$/.test(cardNumber)) {
+        return false;
+    }
+
+    const uniqueDigits = new Set(cardNumber);
+    if (uniqueDigits.size < 2) {
+        return false;
+    }
+
+    if (parseInt(cardNumber[15]) % 2 !== 0) {
+        return false;
+    }
+
+    const sumOfDigits = [...cardNumber].reduce((sum, digit) => sum + parseInt(digit), 0);
+    if (sumOfDigits <= 16) {
+        return false;
+    }
+
+    // If all checks pass, return true
+    return true;
+}
+
+// Test cases
+console.log(validateCreditCard("9999777788880000")); // true
+console.log(validateCreditCard("6666666666661666")); // true
+console.log(validateCreditCard("a92332119c011112")); // false (invalid characters)
+console.log(validateCreditCard("4444444444444444")); // false (only one type of number)
+console.log(validateCreditCard("1111111111111110")); // false (sum less than 16)
+console.log(validateCreditCard("6666666666666661")); // false (odd final number)