12. Asynchronous JavaScript #

Created Monday 15 November 2021

Why #

For computations that take variable time, like network requests, reading files etc.

How #

JavaScript is single threaded and non-blocking. This means that all asynchronous activity must happen in the task queue.

What #

There are three ways to program asynchronous tasks:

1. Callbacks - runs a function when the async task is done/rejected.
2. Promises - this is an object with a state and a value (assigned on completion of task).
3. Async await syntax - syntax sugar to avoid then function chains. Makes code look fully sequential.