const express = require("express");
const app = express();
const port = 3000;

app.get("/", (req, res) => {
  res.send("Hello World!");
});

app.listen(port, () => {
  console.log(`Example app listening on port ${port}`);
});

Basic routing

app.METHOD(PATH, HANDLER);

• app is an instance of express.
• METHOD is and HTTP request method, in lowercase.
• PATH is a path on the server.
• HANDLER is the function executed when the route is matached.

The following examples illustrate defining simple routes.

Respond with Hello World on the homepage.

app.get("/", (req, res) => {
  res.send("Hello World!");
});

Respond to POST request on the root route (/), the application’s home page

app.post("/", (req, res) => {
  res.send("Got a POST request");
});

Respond to a PUT request to the /user route:

app.put("/user", (req, res) => {
  res.send("Got a PUT request at /user");
});

Respond to a DELETE request to the /user route:

app.delete("/user", (req, res) => {
  res.send("Got a DELETE request at /user");
});

For more details about routing, see the express routing guide.