TypeScript For The Win!

Another Typescript ‘AhhHah’ Moment

I just had a lil Typescript success moment and I want to share 🥳. I’m working through this tutorial on binary search trees 🌳. I’m also rewriting it in Typescript just to get more familiar with TS.

I got to this section:

BFS(start) {
  let data = [],
      queue = [],
      current = start ? this.find(start) : this.root;
  queue.push(current);
  while (queue.length) {
    current = queue.shift();
    data.push(current.val);
    if (current.left) queue.push(current.left);
    if (current.right) queue.push(current.right);
  };
  return data;
}

Basically, the author has refactored his breadth-first search method to add a starting point. If a starting point is passed to the method, the breadth-first search starts at that point.

But when I was reworking it in TS, TS yelled “Hey, find() can return something other than an instance of the binary tree! What if what you’re searching isn’t found!”

Oh yeah…how about that!

So I added this to prevent a possible error:

let search: TreeNode | boolean = this.find(start);
let visited = [];
let queue = [];
let current: TreeNode = search instanceof TreeNode ? search : this.root;

I know that probably won’t impress a lot of people, but for me it was nice illustrative moment that answers the “why bother with TS” question for me!