Max Binary Heap implementation in JavaScript

Max Binary Heap.js

//BinaryHeaps are very similar to Binary Tree with some slightly different rules. It has two catagories, Max Binary Heap and Min Binary Heap
//In a Max Binary Heap, parent node is always larger than its child nodes and In a Min Binary Heap, parent node is always smaller than its child node.
//This snippet implementation of Max Binary Heap with JavaScript Arrays.
//Parent idx=n; leftChild idx=[2 * n + 1 ] and rightChild Idx=[2 * n + 2 ]

class MaxBinaryHeap {
  constructor() {
    this.values = [];
  }

  //pushes value at the end of the array and bubbles it way up. It finds it's parent ((idx - 1) / 2) and checks if its larger, if it is -it swaps and this circle goes on.
 insert(element){
        this.values.push(element);
        this.bubbleUp();
    }
  //helper function for insert method
    bubbleUp(){
        let idx = this.values.length - 1;
        const element = this.values[idx];
        while(idx > 0){
            let parentIdx = Math.floor((idx - 1)/2);
            let parent = this.values[parentIdx];
            if(element <= parent) break;
            this.values[parentIdx] = element;
            this.values[idx] = parent;
            idx = parentIdx;
        }
    }

  //This method removes the root/the largest value from the list. And makes the very last element of the list it's root.
  //Than it sinks down to its childens and does the comparison and finds the largest value and makes it the new root.
  extractMax() {
    const max = this.values[0];
    const end = this.values.pop();
    if (this.values.length > 0) {
      this.values[0] = end;
      this.sinkDown();
    }
    return max;
  }
  //helper function for extractMax
  sinkDown() {
    let idx = 0;
    const length = this.values.length;
    const element = this.values[0];
    let loopWillRun = true;
    while (loopWillRun) {
      let leftChildIdx = 2 * idx + 1;
      let rightChildIdx = 2 * idx + 2;
      let leftChild, rightChild;
      let swap = null;
      if (leftChildIdx < length) {
        leftChild = this.values[leftChildIdx];
        if (leftChild > element) {
          swap = leftChildIdx;
        }
      }
      if (rightChildIdx < length) {
        rightChild = this.values[rightChildIdx];
        if (
          (swap === null && rightChild > element) ||
          (swap !== null && rightChild > leftChild)
        ) {
          swap = rightChildIdx;
        }
      }
      if (swap === null) break;
      this.values[idx] = this.values[swap];
      this.values[swap] = element;
      idx = swap;
    }
  }
}


//EXAMPLES==============================================================================

const mxBHeap = new MaxBinaryHeap();

mxBHeap.insert(41);
mxBHeap.insert(39);
mxBHeap.insert(33);
mxBHeap.insert(18);
mxBHeap.insert(27);
mxBHeap.insert(12);
mxBHeap.insert(55);

mxBHeap.extractMax();
mxBHeap.extractMax();

export { mxBHeap };