How do you handle errors with an HTTP request in JavaScript?

Table of Contents

• Introduction
• Error Handling Methods
  • 1. Error Handling with the Fetch API
    • Example
  • Key Points:
  • 2. Error Handling with XMLHttpRequest
    • Example
  • Key Points:
• Conclusion

Introduction

Error handling is crucial when making HTTP requests in JavaScript. It ensures that your application can gracefully manage issues such as network failures, server errors, or invalid responses. This guide explains how to effectively handle errors using both the Fetch API and XMLHttpRequest.

Error Handling Methods

1. Error Handling with the Fetch API

The Fetch API provides a straightforward way to manage errors using promises. You can check the response status and handle different error scenarios accordingly.

Example

Key Points:

• Use response.ok to check if the response was successful.
• Throw an error for non-2xx responses to be caught in the .catch() block.

2. Error Handling with XMLHttpRequest

With XMLHttpRequest, you can handle errors using the onerror event and by checking the HTTP status.

Example

Key Points:

• The onerror event is triggered for network errors.
• Check the xhr.status for server responses and handle accordingly.

Conclusion

Handling errors in HTTP requests is vital for creating robust applications. The Fetch API simplifies error management through promise chaining and response status checks, while XMLHttpRequest provides more detailed control but requires additional code. By implementing effective error handling, you can ensure that your application behaves gracefully in the face of network or server issues.