NodeJS
Understanding Promise.all() and Its Advantages in JavaScript
Introduction
One common scenario that you can run into is working on asynchronous code when you are writing JavaScript for modern webpages. Some cases where promises will be helpful are when fetching data from APIs or performing multiple operations independently. One of the most important features that JavaScript has for managing multiple promises at one time is Promise.all().
What is Promise.all()?
Promise.all() is a method that receive more than one promises and execute them in parallel. Promise. all() resolves the dedicated action when all promises have returned a response. The input promises will be resolved or rejected when the combined promise in the output resolves or rejects.
Use-Case: Fetching Multiple API Endpoints
For instance, suppose you are writing an e-commerce application and you need to fetch the product description, user reviews, and the inventory detail from different APIs simultaneously. In this case, wait for all 3 individual APIs respond isn’t the solution instead, you can issue your calls in parallel using Promise. all().
const getProductDetails = fetch('api/product').then(res => res.json());const getUserReviews = fetch('api/reviews').then(res => res.json());const getInventoryData = fetch('api/inventory').then(res => res.json());Promise.all([getProductDetails, getUserReviews, getInventoryData]) .then(([product, reviews, inventory]) => { console.log('Product:', product); console.log('Reviews:', reviews); console.log('Inventory:', inventory); }) .catch(error => console.error('Error fetching data:', error));Whereas in this case, the waiting time will be lower than the previous one because all the three API calls are executed one after another, concurrently.
Final Thoughts
Concurrency: As All is executed freely, it gives better performance with less waiting time.
Simple Code: With Promise.all(),you can avoid promise nesting and writing multiple. then() statements which will clean up your code and make it easier to handle.
Error Management: With regards to error handling, if one promise fails, Promise.all() will reject immediately, allowing you to stop any unnecessary operations being triggered.
Ready to transform your business with our technology solutions? Contact Us today to Leverage Our NodeJS Expertise.
AI/ML
