Fix card number slice error

Author: Frumentius-Rev

Sprint-2/2-mandatory-errors/3.js

@@ -1,9 +1,19 @@
 const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
+const last4Digits = String(cardNumber).slice(-4);
+console.log(last4Digits);
 
 // The last4Digits variable should store the last 4 digits of cardNumber
 // However, the code isn't working
 // Before running the code, make and explain a prediction about why the code won't work
 // Then run the code and see what error it gives.
 // Consider: Why does it give this error? Is this what I predicted? If not, what's different?
 // Then try updating the expression last4Digits is assigned to, in order to get the correct value
+
+
+// Prediction: TypeError
+// Why: cardNumber is a number, but slice() is a string method.
+
+// Actual error: TypeError: cardNumber.slice is not a function
+// The prediction was correct.
+
+// Fix: convert cardNumber to a string before using slice.