TypeScript is a typed superset of JavaScript that compiles to plain JavaScript.

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Mastering asynchronous code execution is fundamental to becoming a great TypeScript developer. You will learn how [TypeScript](/q/typescript) enables you to write asynchronous code with complete type safety and great runtime support thanks to TypeScript’s understanding of the async / await pattern.

You will learn concepts like Promises, generators and how they enable the runtime environment to allow authoring asynchronous code just as beautifully as synchronous code.

The goal of this course is to give you a solid understanding of how  `async / await` works and how to use it effectively with TypeScript.

To start, we will look at `Promise` basics and see how `.then` and `.catch` are greatly simplified by `async / await`. We will then look at methods for executing asynchronous code in serial (the default), in parallel (with `Promise.all`), and Async iteration.

All with the added benefit of code analysis and error checking by TypeScript. Here's a little intro to the course material. I hope you enjoy the course!

async / await using TypeScript Course Overview

Learn how to write a promise based delay function and then use it in `async await` to see how much it simplifies code over `setTimeout`.

Lets say you want to call a function after 1s, 2s, 3s. You can use `setTimeout`, or you can wrap it up into a simple delay function that works with async/await

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Simplify Asynchronous Callback Functions using async/await

Learn the fundamentals of creating, resolving and rejecting promises using TypeScript. We also cover the fundamentals of a `.then` chain.

We will see how the Promise constructor takes an executor callback which will be called at runtime with two arguments (resolve and reject).

Promise Fundamentals using TypeScript

async / await should really be thought as a better way to use Promises reliably and safely with less chances of programming errors.

This lesson covers the fundamentals of annotating a function as async. An `async` function gets the chance to use the `await` keyword. This lesson covers the usages of these keywords.

Write Async Functions with the async/await Operators

The great thing about asynchronous programming is that you can do multiple things in parallel. E.g. you can make multiple network requests, or read multiple files from the file system. 

This lesson covers how to write parallel as well as serial async code.

Execute Promises in Parallel and Serial using async / await

The `for-await-of` syntax is similar to the `for-of` iteration. The key difference is that it automatically awaits any promises generated by the iterator. This lesson covers how to consume async data sources easily with `for-await-of`.

`for-await-of` essentially allows you to use `async/await` in a generator function.

Async/Await using TypeScript

Basarat Ali Syed

Course Content