Here you can find the source of startsWith(prefix)
'use strict';//from w w w .ja va 2 s. co m var mime = require('mime'); String.prototype.startsWith = function(prefix) { return this.indexOf(prefix) === 0; }; String.prototype.endsWith = function(suffix) { return this.indexOf(suffix, this.length - suffix.length) !== -1; };
String.prototype.startsWith = function (prefix){ return this.slice(0, prefix.length) === prefix; };
String.prototype.startsWith = String.prototype.startsWith || function (prefix){ return this.slice(0, prefix.length) === prefix; };
String.prototype.startsWith = function (prefix) { return this.substring(0, prefix.length) === prefix; };
String.prototype.startsWith = function(prefix) { return this.slice(0, str.length) == str; };
String.prototype.startsWith = function(prefix){ return (this.lastIndexOf(prefix, 0) === 0); };
String.prototype.startsWith = function (prefix){ return this.slice(0, prefix.length) == prefix;
String.prototype.startsWith = function(prefix) if(prefix == null) return false; if(this.length < prefix.length) return false; return this.substring(0, prefix.length) == prefix; }; String.prototype.endsWith = function(suffix) ...
String.prototype.startsWith = function (prefix) { return this.substring(0, prefix.length) == prefix; };
String.prototype.startsWith = function (prefix, ignoreCase) { var _prefix = prefix.source ? prefix.source : prefix.escapeRegExp(); return this.match(new RegExp("^" + _prefix, ignoreCase ? 'i' : '')); }; String.prototype.endsWith = function (suffix, ignoreCase) { var _suffix = suffix.source ? suffix.source : suffix.escapeRegExp(); return this.match(new RegExp(_suffix + "$", ignoreCase ? 'i' : '')); }; String.prototype.escapeRegExp = function() { ...