This javascript adds a method to javascript arrays that returns a boolean indicating if the supplied object is an element of the array Array.prototype.contains = function(item) {
for (var i = 0; i < this.length; i += 1) {
if (this[i] === item) {
return true;
}
}
return false;
};
To test
alert([1,1,1,2,2,22,3,4,5,6,7,5,4].contains(2)); // true
alert([1,1,1,2,2,22,3,4,5,6,7,5,4].contains(99)); // false