Tutorial Javascript Concurrency - Examples

Concurrency

Concurrency in JavaScript refers to the language’s ability to perform multiple operations or tasks at the same time, or manage multiple tasks that are in progress simultaneously. Although JavaScript is single-threaded (meaning it can only execute one task at a time in a single thread), it achieves concurrency through various mechanisms, such as event loops, promises, async/await, web workers, and other asynchronous operations.

Key Concepts of Concurrency in JavaScript

1. Event Loop:

• The event loop is the core mechanism that allows JavaScript to handle asynchronous operations. It continually checks the call stack and the task queue (or message queue) to determine what needs to be executed next.
• When the call stack is empty, the event loop takes the next task from the task queue and pushes it onto the call stack.

2. Callbacks:

• A callback is a function passed to another function as an argument to be executed later, usually after some asynchronous operation has completed.

3. Promises:

• Promises provide a way to handle asynchronous operations by representing the eventual completion (or failure) of an asynchronous operation and its resulting value.

4. Async/Await:

• Async/await is syntactic sugar built on top of promises, providing a more readable and straightforward way to write asynchronous code.

5. Web Workers:

• Web Workers allow you to execute JavaScript in the background, independently of the main thread of execution. This helps you perform computationally intensive tasks without blocking the user interface.

By leveraging the event loop, callbacks, promises, async/await, and web workers, you can effectively manage asynchronous operations, ensuring that your applications remain performant and responsive to user interactions.