Here you can find the source of contains(value)
String.prototype.contains = function contains(value){ return this.indexOf(value) !== -1; };
String.prototype.contains = function(token, ignoreCase) { var _reg = 0, str = this.toString(), i; if(str && typeof token === "string") { if(ignoreCase === true) { token = token.toLowerCase(); str = str.toLowerCase(); while((i = str.indexOf(token)) !== -1) { str = str.substring(i + token.length); ...
String.prototype.contains = function(txt) return (this.indexOf(txt) >= 0);
String.prototype.contains = function (value) { "use strict"; var containsValue = false; if (this.indexOf(value) >= 0) { containsValue = true; return containsValue; };
String.prototype.containsAll = function(strings, index) { if(!Array.isArray(strings)) throw Error('1 argument is not an array'); return strings.every(string => this.includes(string, index), this);
String.prototype.contains = function contains(substring) { return this.indexOf(substring) !== -1; };
String.prototype.onlyContains = function(stringSet) { for (var i=0;i<this.length;i++) { var currentChar = this[i]; if (!stringSet.contains(currentChar)) return false; return true; };
String.prototype.shuffle = function(container){ var str = this, progress = str.length - 2, timer = setInterval(function() { container.text(str.substring(0, progress++)); if (progress > str.length) clearInterval(timer); }, 80);