3.js

const cardNumber = 4533787178994213;
const last4Digits = cardNumber.slice(-4);

// 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


//Answer

// This code is not working because slice() is working with "string" or "arrays" but not with numbers. and cardNumber is a number.
// So the error is "TypeError:cardNumber.slice is not a function"\
// slice() didn't recognize the number as I expected before.

const cardNumber = 4533787178994213;
const last4Digits = String(cardNumber).slice(-4);
console.log(last4Digits)