</> Code Challenge: Check phone number format


// JavaScript code​​​​​​‌‌​‌​‌‌​‌​‌‌‌‌​​‌‌‌​‌​​‌‌ below
// Write your answer here, and then test your code.
// Your job is to implement the isPhoneNumberValid() method.

// Change these boolean values to control whether you see 
// the expected answer and/or hints.
const showExpectedResult = false;
const showHints = false;

const valid = 'Valid Phone Number';
const invalid = 'Invalid Phone Number';
function isPhoneNumberValid(phoneNumber) {
    if (phoneNumber.startsWith('1-')) {
        return valid;
    } else {
        return invalid;
    }
}