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Home Node.js Reference EventEmitter

EventEmitter

class

The foundation of Node.js event-driven architecture. Classes extend EventEmitter to emit and listen to events.

Syntax

const { EventEmitter } = require('events')

Example

javascript
const { EventEmitter } = require('events');

class Shop extends EventEmitter {}

const shop = new Shop();

// Listen for event
shop.on('order', (item) => {
    console.log(`Processing order: ${item}`);
});

// Listen once
shop.once('open', () => console.log('Shop opened!'));

// Emit event
shop.emit('order', 'Laptop');
shop.emit('open');

// Remove listener
shop.off('order', handler);