JSFiddle - React, Tailwind, and code Playground

by Nick

HTML

<input type="text" id="PhoneField" />

JavaScript

$("#PhoneField").val("09---------");

$("#PhoneField").keyup(function () {
  $("#PhoneField").val(function() {
	  var phoneNumber = $(this).val().replace(/-/g, "");
		var curLength = phoneNumber.length;
    // Add correct number of hyphens to front of phone number
    var hyphens = Math.max(12 - phoneNumber.length, 0);
    phoneNumber = phoneNumber + Array(hyphens).join("-");
    // If the first characters are not 09, add them
    if(phoneNumber.substring(0, 2) !== "09") {
    	phoneNumber = "09" + phoneNumber;
    }
		// Impose length limit
    phoneNumber = phoneNumber.substring(0,11);
    return phoneNumber;
  });
});