Express req.query Property

The req.query property allows you to access query parameters from the URL of an incoming HTTP request. Query parameters are key-value pairs added after the ? symbol in a URL and are commonly used to filter, search, or pass optional data to the server.

Syntax:

req.query

Parameter: req.query does not require any parameters. It automatically parses and returns an object containing the query parameters from the URL.

Return Value: Returns an object containing the query parameters as key-value pairs.

Steps to Create the Application:

Step 1: You can install this package by using this command.

npm install express

Step 2: After installing the express module, you can check your express version in the command prompt using the command.

npm version express

Step 3: After that, you can just create a folder and add a file, for example, index.js. To run this file you need to run the following command.

node index.js

Project Structure:

Example 1: Below is the basic example of the req.query property:

const express = require('express');
const app = express();
const PORT = 3000;
app.get('/profile',
    function (req, res) {
        console.log(req.query.name);
        res.send("Query parameter received");
    });
app.listen(PORT,
    function (err) {
        if (err) console.log(err);
        console.log("Server listening on PORT", PORT);
    });

Steps to run the program:

node index.js

Console Output:

Browser Output: Go to http://localhost:3000/profile?name=Gourav :

Example 2: Below is the basic example of the req.query property:

const express = require('express');
const app = express();
const PORT = 3000;
app.get('/user',
    function (req, res) {
        console.log("Name: ", req.query.name);
        console.log("Age:", req.query.age);
        res.send("User details received");
    });
app.listen(PORT,
    function (err) {
        if (err) console.log(err);
        console.log(
            "Server listening on PORT",
            PORT
        );
    });

Steps to run the program:

node index.js

Output: GET request to http://localhost:3000/user?name=Gourav&age=11:

Working of req.query

• The client sends a request containing query parameters in the URL.
• Express parses the query string automatically.
• The parsed parameters are stored in req.query.
• You can access individual values using keys such as req.query.name.

Common Use Cases of req.query

• Filtering data
• Searching records
• Sorting results
• Pagination
• Passing optional request parameters