JavaScript determines whether an array contains a specified element _javascript tips

The example in this article describes how JavaScript determines whether an array contains a specified element. Share to everyone for your reference. Specifically as follows:

This code defines the array method through prototype so that the Contains method can be invoked in any array

/**
 * Array.prototype. [Method name] allows your to define/overwrite a objects method
 * Needle are the item you are searching for
 * this I s a special variable that refers to ' this ' instance an Array.
 * Returns True if Needle is in the array, and False otherwise
/Array.prototype.contains = function (needle) { C7/>for (i in this) {
    if (this[i] = = needle) return true;
  }
  return false;
}

Usage:

Now I can do things like:
var x = Array ();
if (X.contains (' foo ')) {
  //do something special
}

I hope this article will help you with your JavaScript programming.