How do you implement a complete CRUD REST API in Express?

Register one route per HTTP method on the resource - GET, POST, PUT, and DELETE - so each CRUD operation has its own handler.

const express = require('express');
const app = express();
app.use(express.json());

let users = [];

app.get('/users', (req, res) => res.json(users));
/* find */
app.get('/users/:id', (req, res) => { });
/* create */
app.post('/users', (req, res) => { });
/* replace */
app.put('/users/:id', (req, res) => { });
/* remove */
app.delete('/users/:id', (req, res) => { });