The phone number string to be formatted.
The formatted phone number string in the format XXXX-XXXX-XXXX, or null if the input is invalid.
// Assuming `formatPhone` is a regex that matches a 12-digit phone number.
import { formatPhone } from './regex'; // Example: /^\d{4}(\d{4})(\d{4})$/
const validPhone = "123456789012";
console.log(formatPhoneNumber(validPhone)); // "1234-5678-9012"
const invalidPhone = "12345";
console.log(formatPhoneNumber(invalidPhone)); // null
const phoneWithExtraChars = "(123) 456-789012";
console.log(formatPhoneNumber(phoneWithExtraChars)); // "1234-5678-9012"
const emptyPhone = "";
console.log(formatPhoneNumber(emptyPhone)); // null
Formats a phone number string into a specific format.
This function takes a phone number string, removes any non-numeric characters, and formats it into the pattern
XXXX-XXXX-XXXXif the input matches the required structure. If the input is invalid or does not match the format, it returnsnull.