EventEmitter

The base class for objects that emit events in Node.js. Provides on(), once(), emit(), and removeListener() methods.

Syntax

nodejs

const emitter = new EventEmitter();
emitter.on("event", listener);
emitter.emit("event", ...args);

Example

nodejs

const EventEmitter = require("events");
const ee = new EventEmitter();

ee.on("data", (chunk) => {
  console.log("Received:", chunk);
});

ee.once("close", () => console.log("Connection closed"));

ee.emit("data", "hello");