//發(fā)布 emit 訂閱 on  {失戀:['哭','吃','購(gòu)物']}
//一對(duì)多 多對(duì)一的關(guān)系

function Girl() { //創(chuàng)建對(duì)象

    this._events = {} //對(duì)象的事件集合

} // {失戀:[cry]}

Girl.prototype.on = function (eventName, callback) { //訂閱
    if (this._events[eventName]) { //判斷是不是第一次--不是第一次
        this._events[eventName].push(callback); //{失戀：[cry,eat,shopping]}
    } else {
        this._events[eventName] = [callback] //{失戀：[cry]
    }

};

Girl.prototype.emit = function (eventName, ...args) { //發(fā)布

    if (this._events[eventName]) {
        this._events[eventName].forEach(cb => cb.apply(this, args));

        // forEach(cb=>cb(...args));
    }

};


let girl = new Girl();

let cry = (who) => {
    console.log(who + '哭')
};

let eat = (who) => {
    console.log(who + '吃')
};

let shopping = (who) => {
    console.log(who + '購(gòu)物')
};


girl.on('失戀', cry); // {失戀:[cry]
girl.on('失戀', eat); //{失戀:[cry,eat]
girl.on('失戀', shopping); //{失戀:[cry,eat,shopping]

girl.emit('失戀', '我', '你');