How to Get JSON from URL in JavaScript
JavaScript provides several built-in methods for making network requests, including the fetch() method, which allows you to make HTTP requests and handle the response in a promise-based manner. In this tutorial, we’ll explore how to use the fetch() method to get a JSON from a URL in JavaScript.
The first step in getting a JSON from a URL is to define the URL that you want to fetch. This can be any valid URL that returns a JSON response. For example, let’s say we want to fetch a JSON from the following URL: https://jsonplaceholder.typicode.com/todos/1.
To define the URL in JavaScript, you can simply assign a string containing the URL to a variable, like this:
//URL to make request const url = 'https://jsonplaceholder.typicode.com/todos/1'; //rest of the code go here
Next, you can use the fetch() method to make a GET request to the URL and get the JSON response. The fetch() method returns a promise that resolves to the Response object, which contains information about the response, such as the status code, headers, and body.
To get the JSON response from the Response object, you need to call the json() method, which also returns a promise that resolves to the parsed JSON data. Here’s how you can fetch the JSON from the URL:
fetch(url)
.then(response => response.json())
.then(data => {
console.log(data); // log the parsed JSON data to the console
})
.catch(error => {
console.error(error); // log any errors to the console
});
This code sends a GET request to the URL using the fetch() method, and then chains two then() methods to handle the response. The first then() method takes the Response object and calls the json() method to parse the response body as JSON. The second then() method receives the parsed JSON data as an argument and logs it to the console.
If an error occurs during the fetch operation, the catch() method logs the error to the console.
Finally, you can use the parsed JSON data in your code as needed. For example, you could display the JSON data on a web page or use it to update the state of a JavaScript application. Here’s an example of how to display the JSON data on a web page:
fetch(url)
.then(response => response.json())
.then(data => {
const jsonElement = document.createElement('pre');
jsonElement.innerText = JSON.stringify(data, null, 2);
document.body.appendChild(jsonElement);
})
.catch(error => {
console.error(error); // log any errors to the console
});
This code creates a new pre element and sets its text content to the JSON data using the JSON.stringify() method. The third argument to JSON.stringify() is the number of spaces to use for indentation. The code then appends the pre element to the document body, which displays the JSON data as formatted text on the web page.
In this tutorial, we learned how to use the fetch() method to get a JSON from a URL in JavaScript. By following these steps, you can easily fetch JSON data from any URL and use it in your JavaScript applications.
