Create a Startwith Function in JavaScript.

Javascript does not have a StartsWith function so we have to create it manually we use String prototype for create StartsWith function.

if (typeof String.prototype.startsWith != 'function') {
  // see below for better implementation!
  String.prototype.startsWith = function (str){
    return this.indexOf(str) == 0;
  };
}

Then you can use it directly on string values.

"Hello World!".startsWith("He"); // true

var data = "Hello world";
var input = 'He';
data.startsWith(input); // true