Here you can find the source of startsWith(text)
String.prototype.startsWith = function (text) { return this.indexOf(text) == 0; }; var msg = "Hello world!"; print(msg.startsWith("Hello")); //true
"use strict"; String.prototype.startsWith = function(substring) { var substringLength = substring.length; if (substringLength > this.length) { return false; var i; for (i = 0; i < substringLength; i += 1) { if (substring[i] !== this[i]) { ...
String.prototype.startsWith = function(substring) { var compareString = this.substring(0, substring.length); return compareString === substring; };
String.prototype.startsWith = function(prefix) { return (this.indexOf(prefix) == 0); }; module.exports = {};
String.prototype.startsWith = function (suffix) { return !(this.indexOf(suffix) !== 0); };
console.log(typeof Array.prototype.sort); console.log(typeof String.prototype.substring); String.prototype.startsWith = function (text) { return this.indexOf(text) === 0; }; var msg = 'Hello world!'; console.log(msg.startsWith('Hello'));
String.prototype.startsWith = function (text) { return this.substring(0, text.length) === text; };
String.prototype.startsWith = function(text) { return text != null && this.indexOf(text) == 0; };
String.prototype.startsWith= function(value) if (value.length <= this.length) return this.substring(0, value.length) == value; return false; };
String.prototype.startsWith = function (value) { 'use strict'; return this.lastIndexOf(value, 0) === 0; };