Route Parameters

Part of the Express Basics section of Coddy's Node.js journey. Lesson 4 of 20.

Recipe Box will hold many recipes, and one route per recipe would never end.

app.get('/weather/:city', (req, res) => {
    res.send('Forecast for ' + req.params.city);
});

A path part that starts with a colon is a route parameter: it matches any value, and Express puts that value in req.params. GET /weather/oslo sends Forecast for oslo.

A parameter is always a string. GET /rooms/12 gives '12', and '12' === 12 is false, so convert it with Number(...) before comparing it with numbers.

When the thing asked for does not exist, answer status 404: res.status(404).send('No such city') sets the status, then sends.

Challenge

Easy

GET /recipes/:id answers the title of the recipe with that id.
An unknown id answers 404 with No such recipe.

Send GET /recipes/2, then GET /recipes/99.

Try it yourself

import express from 'express';
import { recipes } from './data.js';

const app = express();

app.get('/', (req, res) => {
    res.send('Welcome to Recipe Box');
});

// type('text') sends plain text, so each title shows on its own line.
app.get('/recipes', (req, res) => {
    res.type('text').send(recipes.map((recipe) => recipe.title).join('\n'));
});

app.get('/about', (req, res) => {
    res.send('Recipe Box collects family recipes.');
});

app.listen(3000, () => {
    console.log('Recipe Box is running on port 3000');
});