How to use Promise.all() with map In Javascript
- In this appraoch, we are creating a function in which we are creating a promise.
- We are creating another function and returning a promise. in which we are using setTimeout() function to print the item in th console.
- After that we are declaring an array and passing it to the above created function.
Example: This example shows the implementation of the above-explained approach.
Javascript
async function processArray(array) { await Promise.all(array.map(async item => { await someAsyncFunction(item); })); } async function someAsyncFunction(item) { // Simulating an asynchronous operation return new Promise(resolve => { setTimeout(() => { console.log(item); resolve(); }, 1000); }); } const myArray = [1, 2, 3, 4, 5]; processArray(myArray); |
Output:
Explanation: Due to the delay in printing elements, another element ” for ” is printed before the first element “geeks” in myArray to save time. It depicts that the asynchronous function run simultaneously.
How to use async/await with forEach loop in JavaScript ?
Asynchronous is popular nowadays because it gives functionality of allowing multiple tasks to be executed at the same time (simultaneously) which helps to increase the productivity and efficiency of code.
Async/await is used to write asynchronous code. In JavaScript, we use the looping technique to traverse the array with the help of forEach loop.
NOTE: Using
async/await
withforEach
loop in JavaScript can be a bit tricky sinceforEach
doesn’t inherently support asynchronous operations
Table of Content
- Using async/await in for…of loop
- Using Promise.all() with map