javascript - 创建自定义 EventEmitter 时是否需要 events.EventEmitter.call(this)？

Question

有很多示例在自定义事件发射器构造函数中未使用 events.EventEmitter.call(this)，而其他示例正在使用它 (official documentation):

var events = require('events')
  , util   = require('util');

var MyEmitter = function () {
    events.EventEmitter.call(this);
};

util.inherits(MyEmitter, events.EventEmitter);

MyEmitter.prototype.write = function () {
    this.emit('tick');
};

以我对 JavaScript 的基本了解，我不知道是否需要它。是否需要调用以初始化 EventEmitter 中的内容？

Answer 1

是的，是的。

在 Node 0.10 之前，如果您忘记它也不会崩溃。

现在，it will :

The EventEmitter constructor initializes various properties now. It still works fine as an OOP inheritance parent, but you have to do inheritance properly. The Broken-Style JS inheritance pattern will not work when extending the EventEmitter class. This inheritance style was never supported, but prior to 0.10, it did not actually break.