res.status for status codes in Express - Mini Project: Build & Apply

Using res.status to Send HTTP Status Codes in Express

📖 Scenario: You are building a simple Express server that responds to client requests. You want to send proper HTTP status codes to tell the client if the request was successful or if there was an error.

🎯 Goal: Build an Express route that uses res.status to send different HTTP status codes along with messages.

📋 What You'll Learn

Create an Express app with a GET route at /status

Add a variable isSuccess to control the response status

Use res.status to send 200 if isSuccess is true

Use res.status to send 500 if isSuccess is false

Send a JSON message with a message property describing the status

💡 Why This Matters

🌍 Real World

Web servers use HTTP status codes to tell browsers or apps if requests worked or failed. This helps users understand what happened.

💼 Career

Backend developers must send correct status codes to build reliable APIs and web services.

1

Set up Express app and route

Create an Express app by requiring express and calling express(). Then create a GET route at /status with a callback function that takes req and res as parameters.

Express

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

// Create GET route at /status
// Your code here

Need a hint?

Remember to require Express and create an app instance. Use app.get to define the route.

2

Add a variable to control success

Inside the /status route callback, create a variable called isSuccess and set it to true.

Express

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

app.get('/status', (req, res) => {
  // Create variable isSuccess and set to true
  // Your code here
});

Need a hint?

Just create a constant named isSuccess and assign it the value true.

3

Send status 200 or 500 based on isSuccess

Use an if statement to check if isSuccess is true. If yes, use res.status(200) and send a JSON object with { message: 'Success' }. Otherwise, use res.status(500) and send { message: 'Error' }.

Express

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

app.get('/status', (req, res) => {
  const isSuccess = true;
  // Use if to check isSuccess and send status and JSON message
  // Your code here
});

Need a hint?

Use res.status(code).json(object) to send status and JSON response.

4

Start the server on port 3000

Add code to start the Express server by calling app.listen on port 3000 with a callback that logs 'Server running on port 3000'.

Express

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

app.get('/status', (req, res) => {
  const isSuccess = true;
  if (isSuccess) {
    res.status(200).json({ message: 'Success' });
  } else {
    res.status(500).json({ message: 'Error' });
  }
});

// Start server on port 3000
// Your code here

Need a hint?

Use app.listen(port, callback) to start the server and log a message.