Js function implementation method to determine whether an array contains an element. array js

Js function implementation method to determine whether an array contains an element. array js

Js function implementation method for determining whether an array contains an element

Array.prototype.contains = function(obj) {  var i = this.length;  while (i--) {    if (this[i] === obj) {      return true;    }  }  return false;}

Or

Array.prototype.contains = function(element) {  for (var i = 0; i < this.length; i++) {    if (this[i] == element) {      return true;    }  }  return false;}

Or

Array.prototype.in_array = function(e) {  for(i=0; i<this.length && this[i]!=e; i++);  return !(i==this.length);}

Another Daniel wrote the following:

Array.prototype.S = String.fromCharCode(2);Array.prototype.in_array = function(e) {  var r = new RegExp(this.S+e+this.S);  return (r.test(this.S+this.join(this.S)+this.S));}

The usage is as follows:

Var arr = ["a", "B"];

Alert (arr. in_array (""))

It is said that while subtraction iteration is the fastest method in js. I don't know if it is true.

Http://stackoverflow.com/questions/237104/javascript-array-containsobj

The discussion here is very intense. We suggest you check it out. If jQuery is used, you can directly use the method implemented by jQuery. refer:

Http://api.jquery.com/jQuery.inArray/

The js function implementation method used to determine whether the array contains an element is all the content shared by Alibaba Cloud xiaobian. I hope to give you a reference and support for the help house.