In Node.js, asynchronous programming is both straightforward and effective. When working with Node.js modules, you'll notice that most modules provide both synchronous and asynchronous methods. It is recommended to use asynchronous methods whenever possible due to their non-blocking nature, which enhances performance and speed.
If an asynchronous method is not available for a specific operation, you can leverage third-party modules to perform various tasks asynchronously.
There are three primary techniques for asynchronous programming in Node.js: callbacks, promises, and async/await.
1. Callback: Callbacks are functions passed as arguments to asynchronous functions. They execute once the asynchronous operation is complete, following a "do this, once you're done doing that" approach. Callbacks are useful for executing tasks that depend on the completion of an asynchronous function, such as logging the output it returns or implementing serial operations.
const fs = require('fs');
fs.readFile('hello.txt', 'utf8', (err, data) => {
console.log(data);
});
2 . Promises: Node.js modules often provide promise-based API methods that return promises. These promise-based methods, like
fs.promises.readFile introduced in Node.js 10.0.0, enable asynchronous programming in a non-blocking manner. Promises are beneficial for managing asynchronous code flow.
const fs = require('fs');
fs.promises.readFile('hello.txt', 'utf8')
.then(data => {
console.log(data);
});
3. Async/Await: Async/Await is a newer concept that can be used with promise-based API methods. It provides a more readable and synchronous-like way to handle asynchronous code.
const fs = require('fs');
async function readFileAsync() {
const data = await fs.promises.readFile('hello.txt', 'utf8');
console.log(data);
}
readFileAsync();
These three techniques offer flexibility in handling asynchronous operations in Node.js, making it a versatile platform for building high-performance and responsive applications.
