Making an HTTP request in JavaScript is a common task that many developers need to do in order to retrieve data from a server or to send data to a server. In this blog post, we will explore the different ways to make an HTTP request in JavaScript, including the use of the XMLHttpRequest object and the fetch API.
The XMLHttpRequest object is the oldest method for making an HTTP request in JavaScript. This object allows you to send an HTTP request and handle the response using JavaScript. To create an XMLHttpRequest object, you can use the following code:
var xhr = new XMLHttpRequest();Once you have created the XMLHttpRequest object, you can use the open() method to specify the type of request you want to make (GET, POST, etc.), the URL you want to make the request to, and whether the request should be synchronous or asynchronous. For example, to make a GET request to a specific URL, you can use the following code:
xhr.open("GET", "https://example.com", true);xhr.send();After you have opened the request, you can use the send() method to send the request to the server.
You can also handle the response from the server by setting an onreadystatechange event listener on the XMLHttpRequest object. The readyState property of the object will change as the request is sent and a response is received. The status property will contain the HTTP status code of the response. For example, you can use the following code to handle the response:
xhr.onreadystatechange = function() { if (xhr.readyState === 4 && xhr.status === 200) { console.log(xhr.responseText); }};The responseText property of the XMLHttpRequest object will contain the response from the server.
The fetch API is a more recent method for making an HTTP request in JavaScript. The fetch API is built on top of the XMLHttpRequest object, but it is more modern and easier to use. To make a request using the fetch API, you can use the fetch() function and pass in the URL you want to make the request to. For example, to make a GET request to a specific URL, you can use the following code:
fetch("https://example.com") .then(response => response.text()) .then(data => console.log(data)) .catch(error => console.log(error));The fetch() function returns a promise that resolves the response from the server. The then() method can be used to handle the response. The response object has several properties that can be used to determine the status of the response, including the ok property, which will be true if the status code of the response is 200-299, and the status property, which will contain the HTTP status code of the response.
The text() method can be used to extract the response data as a string. The catch() method can be used to handle errors that occur when making the request. In addition, to GET requests, you can also make POST, PUT, PATCH, and DELETE requests using the fetch API. To make a POST request, you can pass in an options object.
