jQuery determines whether the array contains the specified elements

To determine whether an array contains an element, in principle, is to walk through the entire array and determine if it is equal,

var arr = [ "xml", "html", "css", "js" ]; 

$.inArray("js", arr);  // return  3,

If it is not in the array, -1 is returned.

The above is the entire content of this article, there is a need for the companion reference