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Asynchronous programming in JavaScript using promises and async/await

Ashish Kasama|12/8/2022, UTC|3 MIN READ|

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/Asynchronous programming in JavaScript using promises and async/await

Asynchronous programming is an important concept in JavaScript, and it refers to the ability of a program to perform multiple tasks concurrently. This is especially important in JavaScript because it is a single-threaded language, which means that it can only execute one task at a time.

There are several ways to perform asynchronous programming in JavaScript, including using callback functions, promises, and the async/await syntax.

A callback function is a function that is passed as an argument to another function and is executed when the first function completes. For example:

function getData(callback) {

  // simulate a long-running task

  setTimeout(function() {

    var data = "some data";

    callback(data);

  }, 1000);

getData(function(data) {

  console.log(data);

}

);

In this example, the "getData" function simulates a long-running task and then calls the callback function with the "data" argument when it completes.

Promises are another way to perform asynchronous programming in JavaScript. A promise is an object that represents the result of an asynchronous operation, and it can be either fulfilled (resolved) or rejected. Promises can be used to simplify the process of working with async operations, and they can be chained together using the "then" method. For example:

function getData() {

  return new Promise(function(resolve, reject) {

    // simulate a long-running task

    setTimeout(function() {

      var data = "some data";

      resolve(data);

    }, 1000);

});

getData().then(

function(data) {

  console.log(data);

});

In this example, the "getData" function returns a promise that is resolved with the "data" argument after a 1-second delay. The "then" method is used to

Check out the rest of our series on Javascript by reading our other articles.