A JS implementation of a Heap. HeapSort function also provided.

Heap.js

var Heap = function(input) {

    this.arrayLength =  input.length ;

    for(var j= Math.floor(this.arrayLength / 2);j>=0; j--) {
        this.heapify(input,j);
        console.log(j);
    }


};

Heap.prototype.swap = function (array,a,b) {
    var temp = array[a];
    array[a] = array[b];
    array[b] = temp;
};

Heap.prototype.heapify = function(input,i) {

    var left = 2*i + 1;
    var right = 2*i + 2;
    var parent = i;

    if(left < this.arrayLength && input[left] > input[parent] ) {
        parent = left;
    }

    if(right < this.arrayLength && input[right] > input[parent] ) {
        parent = right;
    }

    if(parent != i) {
        this.swap(input,i,parent);
        this.heapify(input,parent);
    }


} ;

Heap.prototype.heapSort = function(input) {
    for (var i=input.length - 1; i > 0; i--) {
        this.swap(input,0,i);
        this.arrayLength--;
        this.heapify(input,0);
    }
};


var input = [3,1,4,5,6,2];
var h = new Heap(input);
h.heapSort(input);
console.log(input);