req.cookies holds the cookies sent by the client. It's populated by the cookie-parser
middleware.
Syntax
req.cookies
Example
const express = require("express");
const cookieParser = require("cookie-parser");
const app = express();
const PORT = 4700;
app.use(cookieParser());
app.get("/set-theme", (req, res) => {
res.cookie("theme", "dark");
res.send("Theme cookie set");
});
app.get("/read-theme", (req, res) => {
res.send(`Current theme: ${req.cookies.theme}`);
});
app.listen(PORT, () => console.log(`Listening on ${PORT}`));
Visiting /set-theme then /read-theme returns Current theme: dark.
Use cases
- Reading a user's saved preferences.
- Reading session identifiers.
- Reading authentication-related cookie values.