Science Knowings: JavaScript Course For Social Media

XMLHttpRequest Object

XMLHttpRequest Object

Welcome back! In this session, we'll delve into the XMLHttpRequest object, the cornerstone of asynchronous communication in JavaScript.

What is XMLHttpRequest?

XMLHttpRequest is an object that allows you to make HTTP requests from JavaScript code, enabling dynamic data exchange without refreshing the page.

Creating an XMLHttpRequest Object

To create an XMLHttpRequest object, you use the new XMLHttpRequest() constructor. This creates a new instance of the object that you can use to make HTTP requests.


XMLHttpRequest allows you to use different HTTP methods to perform various operations on the server. The most common methods are GET, POST, PUT, and DELETE, each serving specific purposes.

Sending HTTP Requests

To send an HTTP request using XMLHttpRequest, you use the open() and send() methods. open() specifies the request type, URL, and other parameters, while send() actually initiates the request.

Handling HTTP Responses

When the server responds to your request, you can access the response data using properties like status, statusText, and responseText. These properties provide information about the HTTP response and the data returned by the server.

Example: Making an AJAX Request

AJAX (Asynchronous JavaScript and XML) is a technique that uses XMLHttpRequest to make asynchronous requests without reloading the page. Here's an example of how to make an AJAX request in JavaScript:

XMLHttpRequest Methods

XMLHttpRequest has a range of methods to control the request and response process. Some commonly used methods include abort(), getAllResponseHeaders(), and setRequestHeader().

Advantages of XMLHttpRequest

XMLHttpRequest offers several advantages, including asynchronous communication, cross-origin requests (CORS), and the ability to cancel or modify requests.

Disadvantages of XMLHttpRequest

Despite its strengths, XMLHttpRequest also has some disadvantages, such as limited support for modern HTTP features, complex event handling, and potential security issues.

Next Topic: Fetch API Methods

In the next session, we'll explore the Fetch API, a modern and improved alternative to XMLHttpRequest. Follow us to learn more about its advantages and how to use it effectively!