`emitter.emit()`

Synchronously invokes every listener registered for the named event.

Since Node 0.x Spec ↗

Syntax

emitter.emit(eventName[, ...args])

Parameters

Name	Type	Required	Description
`eventName`	`string \| symbol`	Yes	The event to emit.
`args`	`...any`	No	Arguments passed to each listener.

Returns

boolean — true if the event had listeners, otherwise false.

Examples

import { EventEmitter } from 'node:events';

const ee = new EventEmitter();
ee.on('add', (a, b) => console.log(a + b));
const had = ee.emit('add', 2, 3);
console.log('handled:', had);

Output

5
handled: true

import { EventEmitter } from 'node:events';

const ee = new EventEmitter();
ee.on('error', (e) => console.log('caught', e.message));
ee.emit('error', new Error('boom'));

Output

caught boom

Notes

Listeners run synchronously and in order before `emit` returns. Emitting `'error'` with no listener throws. An exception thrown by one listener prevents later listeners from running.