Express HTTP methods

HTTP methods tell the server what kind of operation to perform on a resource — fetch it, create it, replace it, or remove it. Express maps each method to its own routing function.

GET

Fetches data from the server.

app.get("/products", (req, res) => {
    res.send("List of products");
});

POST

Sends data to the server, usually to create something.

app.post("/products", (req, res) => {
    res.send("Product created");
});

PUT

Replaces an existing resource with new data.

app.put("/products/:id", (req, res) => {
    res.send(`Product ${req.params.id} fully updated`);
});

DELETE

Removes a resource.

app.delete("/products/:id", (req, res) => {
    res.send(`Product ${req.params.id} removed`);
});

PATCH

Applies a partial update to a resource.

app.patch("/products/:id", (req, res) => {
    res.send(`Product ${req.params.id} partially updated`);
});

Putting it together

const express = require("express");
const app = express();
const PORT = 5000;

app.use(express.json());

app.get("/", (req, res) => res.send("Inventory Service"));
app.post("/products", (req, res) => res.send("Product created"));
app.put("/products/:id", (req, res) => res.send(`Product ${req.params.id} updated`));
app.delete("/products/:id", (req, res) => res.send(`Product ${req.params.id} deleted`));

app.listen(PORT, () => console.log(`Listening on ${PORT}`));

Extra response helpers

Method	Description
`res.download()`	Prompts a file download.
`res.redirect()`	Redirects the client to a different URL.
`res.render()`	Renders a view template.
`res.sendFile()`	Sends a file.
`res.sendStatus()`	Sets the status code and sends its text as the body.
`res.end()`	Ends the response manually.
`res.json()`	Sends a JSON response.
`res.jsonp()`	Sends JSON with JSONP support.