'this' example for a microwave

microwaveExample.js

(function() {
    "use strict"
    
    const microwave = {
        _timer: null,
        _eventListener: null,
        start: function(timeMS, callback) {
            this._eventListener = callback
            this._timer = setTimeout((() => {
                this._timer = null
                this._eventListener('done')
            }).bind(this), timeMS)
        },
        stop: function() {
            if (this._timer) {
                clearTimeout(this._timer)
                this._timer = null
                this._eventListener = null
                return true
            } else {
                return false
            }
        },
        isRunning: function() {
            return !!this._timer
        }
    }

    microwave.start(10000, console.log)
    console.log(microwave.isRunning()) // true
    console.log("stopped: ", microwave.stop()) // stopped: true
    console.log(microwave.isRunning()) // false
    microwave.start(100, console.log) // .... done
})();