Completed the credit card validator

Author: M-Abdoon

Sprint-3/3-stretch/credit-card-validator.js

@@ -0,0 +1,40 @@
+function validateCreditCard(cardNumber)
+{
+    let sum = 0;
+    let allSame = "";
+    cardNumber = String(cardNumber);
+
+    if(cardNumber.length != 16)
+        return false;
+
+    if((cardNumber.slice(-1) % 2) != 0)
+        return false;
+    
+    for (let i = 0; i < cardNumber.length; i++) {
+        sum += Number(cardNumber[i]);
+        if( cardNumber[i] < "0" || cardNumber[i] > "9" ) {
+            return false;
+        }
+    }
+
+    for (let i = 0; i < cardNumber.length; i++) {
+        if("0123456789".includes(cardNumber[i]) && !String(allSame).includes(cardNumber[i])) {
+            allSame += cardNumber[i];
+        }
+    }
+    if(allSame.length < 2) {
+        return false;
+    }
+
+    if(sum < 16)
+        return false;
+
+    return true;
+}
+
+console.log(validateCreditCard("9999777788880000")); // true
+console.log(validateCreditCard("6666666666661666")); // true
+console.log(validateCreditCard("a92332119c011112")); // false
+console.log(validateCreditCard("4444444444444444")); // false
+console.log(validateCreditCard("1111111111111110")); // false
+console.log(validateCreditCard("6666666666666661")); // false