Using Promise.all in Node.js: A Step-by-Step Guide

Promise.all is a method in the JavaScript Promises API that allows developers to handle multiple asynchronous operations in parallel.

Step 1: Import the Promise Object

const Promise = require('promise');

Step 2: Create an Array of Promises

const promise1 = new Promise((resolve, reject) => {
    setTimeout(resolve, 100, 'foo');
});

Examples

Fetching Data from Multiple API Endpoints

const axios = require('axios');

const promises = [
    axios.get('https://jsonplaceholder.typicode.com/todos/1'),
    axios.get('https://jsonplaceholder.typicode.com/todos/2'),
    axios.get('https://jsonplaceholder.typicode.com/todos/3')
];

Promise.all(promises)
    .then(responses => {
        console.log(responses.map(response => response.data));
    })
    .catch(error => {
        console.log(error);
    });

Conclusion

Promise.all enables parallel execution of multiple asynchronous operations in Node.js applications.