本文实例讲述了JavaScript判断数组是否包含指定元素的方法。分享给大家供大家参考。具体如下：

这段代码通过prototype定义了数组方法，这样就可以在任意数组调用contains方法

/**

* Array.prototype.[method name] allows you to define/overwrite an objects method

* needle is the item you are searching for

* this is a special variable that refers to "this" instance of an Array.

* returns true if needle is in the array, and false otherwise

*/

Array.prototype.contains = function ( needle ) {

for (i in this) {

if (this[i] == needle) return true;

}

return false;

}

用法：

// Now you can do things like:

var x = Array();

if (x.contains('foo')) {

// do something special

}

希望本文所述对大家的javascript程序设计有所帮助。