I'm trying to figure out where the number 1 comes from (in the example below you write any phone number and press Backspace many times). Can you please tell me what is wrong in this code?
const input = document.querySelector('input[name="phone"]');
input.addEventListener('input', function () {
let x = input.value;
x = x.replace(/^\+1 /, '');
x = x.replace(/\D/g, '').match(/(\d{0,3})(\d{0,3})(\d{0,2})(\d{0,2})/);
x = !x[2] ? x[1] : x[1] + ' ' + x[2] + (x[3] ? `-${x[3]}` : '') + (x[4] ? `-${x[4]}` : '');
x = x.startsWith('+1 ') ? x : '+1 ' + x;
input.value = x;
});<input name="phone" placeholder="Phone number">