Broken Associative Array of JavaScript

The Associative Array (Perl’s name: Hash) in JavaScript is broken. It is poorly implemented for sake of backward compatibility. However, it can be a nightmare:

var hash = new Array();
if (hash["clear"]==null) {
    hash["clear"]=1;
};

The above code will never set hash["clear"] to 1 because the key clear is already defined. The reason is that, clear() is a function to array and hash is an instance of array. So the key is mapped to a function!

To make it works, consider these variations:

var hash = new Array();
if (hash["clear"]===undefined) {
    hash["clear"]=1;
};

var hash = new Array();
if (hash["clear"]!="function" && hash["clear"]==null) {
    hash["clear"]=1;
};