How do you get query string values in JavaScript?
JavaScript
The short answer
Use the URLSearchParams API. It parses the query string and provides methods to get, set, and iterate over parameters. It is built into the browser and works with any URL.
Using URLSearchParams
javascript
// URL: https://example.com?search=react&page=2&sort=newestconst params = new URLSearchParams(window.location.search);params.get('search'); // "react"params.get('page'); // "2"params.get('sort'); // "newest"params.get('missing'); // null
Other useful methods
javascript
const params = new URLSearchParams('?name=John&age=30&hobby=coding&hobby=reading');params.has('name'); // trueparams.getAll('hobby'); // ["coding", "reading"]params.toString(); // "name=John&age=30&hobby=coding&hobby=reading"// Iterate over all parametersfor (const [key, value] of params) {console.log(`${key}: ${value}`);}
Building query strings
javascript
const params = new URLSearchParams();params.set('search', 'react hooks');params.set('page', '1');console.log(params.toString()); // "search=react+hooks&page=1"// Use with fetchfetch(`/api/products?${params.toString()}`);
Using the URL API
For parsing full URLs (not just the current page):
javascript
const url = new URL('https://example.com/search?q=react&page=2');url.searchParams.get('q'); // "react"url.pathname; // "/search"url.hostname; // "example.com"
Interview Tip
Show new URLSearchParams(window.location.search) and .get(). That is the modern answer. If the interviewer asks about the old way, the manual approach was splitting the string with split('&') and split('='), but URLSearchParams replaced all of that.
Why interviewers ask this
This tests basic web API knowledge. Query strings are used everywhere — search pages, filters, pagination. Knowing URLSearchParams shows you use modern browser APIs instead of manual string parsing.