Mastering Error Handling in Promises: Leveraging catch() and then() Chains in JavaScript

Learn best practices for catching and handling errors in JavaScript promises with real-world code examples

Photo by Janita Sumeiko on Unsplash

JavaScript promises offer a convenient approach to dealing with asynchronous tasks while avoiding the pitfalls of nested callbacks. Proper error handling becomes paramount when working with promises to ensure smooth operation and prevent unintended consequences. Fortunately, promises come equipped with built-in mechanisms like catch() and then() methods for effective error management.

In this post, we will walk through various techniques and strategies for handling errors in promises, complemented with practical code snippets.

Catch Method

The most direct way to capture errors in promises involves employing the catch() method. Adding catch() to a promise chain ensures that any exception thrown along the path is captured and handled appropriately. For instance:

fetch('https://api.example.com/endpoint', {
  method: 'GET',
})
  .then(response => response.json())
  .catch(error => console.error(`Fetch error: ${error}`));