res.cookie() Function

res.cookie() sets a cookie on the client by adding a Set-Cookie header to the response.

Syntax

res.cookie(name, value [, options])

Example

const express = require("express");
const app = express();
const PORT = 4800;

app.get("/login", (req, res) => {
    res.cookie("sessionId", "abc123", {
        maxAge: 3600000,
        httpOnly: true,
    });
    res.send("Logged in, session cookie set");
});

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

Use cases

• Storing session identifiers.
• Remembering user preferences (theme, language).
• Setting short-lived cookies with security options like httpOnly and secure.