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Module

std/node/events.ts>EventEmitter#on

Deno standard library
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The Standard Library has been moved to JSR. See the blog post for details.
method EventEmitter.prototype.on
import { EventEmitter } from "https://deno.land/std@0.175.0/node/events.ts";

Adds the listener function to the end of the listeners array for the event named eventName. No checks are made to see if the listener has already been added. Multiple calls passing the same combination of eventNameand listener will result in the listener being added, and called, multiple times.

server.on('connection', (stream) => {
  console.log('someone connected!');
});

Returns a reference to the EventEmitter, so that calls can be chained.

By default, event listeners are invoked in the order they are added. Theemitter.prependListener() method can be used as an alternative to add the event listener to the beginning of the listeners array.

const myEE = new EventEmitter();
myEE.on('foo', () => console.log('a'));
myEE.prependListener('foo', () => console.log('b'));
myEE.emit('foo');
// Prints:
//   b
//   a

Parameters

eventName: string | symbol

The name of the event.

listener: (...args: any[]) => void

The callback function