node.js中的addListener(event，listener)和on(event，listener)方法之间有什么区别? [英] What is the difference between addListener(event, listener) and on(event, listener) method in node.js?

问题描述

在这里，我无法理解这两种方法之间的基本区别.

Here i cannot understand what is the basic difference between these two methods.

var events = require('events');
var eventEmitter = new events.EventEmitter();



var listner1 = function listner1() {
    console.log('listner1 executed.');
}

var listner2 = function listner2() {
    console.log('listner2 executed.');    
}

eventEmitter.addListener('connection', listner1);

eventEmitter.on('connection', listner2);

eventEmitter.emit('connection');

推荐答案

.on()与EventEmitter对象中的.addListener()完全相同.

.on() is exactly the same as .addListener() in the EventEmitter object.

直接从 EventEmitter源代码:

EventEmitter.prototype.on = EventEmitter.prototype.addListener;

在GitHub存储库中进行搜索，有此签入从2010年7月3日开始，其中包含以下注释: 实验性:'on'作为'addListener'的别名" .

Sleuthing through the GitHub repository, there is this checkin from Jul 3, 2010 that contains the comment: "Experimental: 'on' as alias to 'addListener'".

2017年更新:EventEmitter.prototype.addListener() 文档现在这样说:

emitter.on(eventName, listener)的别名.

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