Jason Kim's Blog

I have been using ES2015 actively using Babe.js and I was already convinced that compiling more dev-friendly language to javascript is useful. One of the langauges that has been praised a lot in this domain is Typescript.

Install Typescript

$ yarn global add typescript

If you get an error saying tsc command is not found, check out this SO answer on this issue.

Linked list in Typescript

Here is a linked list you can start to play with written in Typescript.

// index.ts

import { Node } from './node';

export class List {
  head: Node;
  tail: Node;

  constructor() {
  }

  push(val) {
    let node = new Node(val);
    node.next = this.head;
    this.head = node;
  }

  print() {
    let node = this.head;
    while (node !== undefined) {
      console.log(node.val);
      node = node.next;
    }
  }
}

// list.ts

import { Node } from './node';

export class List {
  head: Node;
  tail: Node;

  constructor() {
  }

  push(val) {
    let node = new Node(val);
    node.next = this.head;
    this.head = node;
  }

  print() {
    let node = this.head;
    while (node !== undefined) {
      console.log(node.val);
      node = node.next;
    }
  }
}

// node.ts

export class Node {
  val: number;
  next: Node;

  constructor(val) {
    if (!val) {
      return;
    }

    this.val = val;
  }
}

Now compile typescript into javascript.

$ tsc index.ts

This should generate index.js, list.js and node.js.

Let's run these javascript files.

$ node index.js

This should print

3
2
1

What I think about Typescript after using it for an hour

Learning Typescript was intuitive and JS I was writing felt more precise and controlled. This allowed me write less error prone javascript in a short period time. I should learn more about tooling around Typescript so that it feels more integrated into the javascript development workflow.