Express.js | app.all() Function

The app.all() function is used to route all types of HTTP requests. Like if we have POST, GET, PUT, DELETE, etc, requests made to any specific route, let’s say /user, so instead of defining different APIs like app.post(‘/user’), app.get(‘/user’), etc, we can define single API app.all(‘/user’) which will accept all type of HTTP request. 

Syntax:

app.all( path, callback )

Parameters:

• Path: It is the path for which the middleware function is called.
• Callback: It can be a middleware function or a series/array of functions.

Installation of the express module:

You can visit the link to Install the express module. You can install this package by using this command.

npm install express

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

npm version express

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:

Filename: index.js

javascript

const express = require('express');
const app = express();
const PORT = 3000;

app.all('/user', function (req, res, next) {
    console.log('USER API CALLED');
    next();
});

app.listen(PORT, function (err) {
    if (err) console.log(err);
    console.log("Server listening on PORT ", PORT);
});

Steps to run the program:

Make sure you have installed the express module using the following command:

npm install express

Run the index.js file using the below command:

node index.js

Output:

Console Output:

Server listening on PORT 3000

Browser Output:

Now open your browser and make GET, POST, PUT, DELETE, or any other HTTP request method to http://localhost:3000/user and you will see the following output on the console:

Server listening on PORT 3000
USER API CALLED