Method chaining on response in Express - Mini Project: Build & Apply

Method Chaining on Express Response

📖 Scenario: You are building a simple web server using Express.js. You want to send a response to the client that sets a status code, a header, and sends a message all in one smooth chain of commands.

🎯 Goal: Build an Express route handler that uses method chaining on the res (response) object to set the status code to 200, set the Content-Type header to text/plain, and send the text Hello, Express!.

📋 What You'll Learn

Create an Express app with a GET route at '/'

Use method chaining on the res object inside the route handler

Set the status code to 200 using status()

Set the Content-Type header to text/plain using set()

Send the response text Hello, Express! using send()

💡 Why This Matters

🌍 Real World

Web servers often need to send responses with specific status codes, headers, and body content. Method chaining on the response object makes this process smooth and readable.

💼 Career

Understanding Express response method chaining is essential for backend developers building APIs and web servers with Node.js and Express.

1

Set up Express app and route

Write code to import Express, create an app with express(), and add a GET route at '/' with a callback function that takes req and res parameters.

Express

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

// Your code here

Need a hint?

Use require('express') to import Express. Then call express() to create the app. Use app.get('/', (req, res) => { }) to add the route.

2

Add status code configuration

Inside the GET route callback, use the res.status(200) method to set the HTTP status code to 200.

Express

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

app.get('/', (req, res) => {
  // Set status code to 200
  // Your code here
});

Need a hint?

Use res.status(200) to set the status code.

3

Chain setting the Content-Type header

Extend the method chain on res to add .set('Content-Type', 'text/plain') after setting the status code.

Express

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

app.get('/', (req, res) => {
  // Chain setting Content-Type header
  // Your code here
});

Need a hint?

Chain .set('Content-Type', 'text/plain') right after res.status(200).

4

Complete the response with send()

Complete the method chain by adding .send('Hello, Express!') to send the response text to the client.

Express

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

app.get('/', (req, res) => {
  // Complete the chain with send()
  // Your code here
});

Need a hint?

Add .send('Hello, Express!') at the end of the method chain.