javascript - Accessing object properties from object itself -

javascript - Accessing object properties from object itself -

i'm having little problem learning object-oriented javascript. have 2 classes called cosmos , background, cosmos looks this:

// js/cosmos.js function cosmos() { this.background = new background(); // fire game loop this.ticker = setinterval(this.tick, 1000 / 60); } // main game loop cosmos.prototype.tick = function() { console.log(this.background); }

when main game loop ticks, undefined in console. don't quite understand because this.background property of cosmos class, should accessible methods defined in cosmos class, no?

if go index.html page's script tag , alter this:

// lift off var cosmos = new cosmos(); console.log(cosmos.background);

it works , background object gets logged console. can offer explanation , tell me how can access properties of cosmos within cosmos.tick?

edit: turns out problem setinterval(), because if proper object logged console:

function cosmos() { this.background = new background(); // fire game loop //this.ticker = setinterval(this.tick, 1000 / 60); this.tick(); } // main game loop cosmos.prototype.tick = function() { console.log(this.background); }

still don't know best way around it, though.

when function called setinterval, this not bound object anymore.

this quick prepare problem:

// js/cosmos.js function cosmos() { var self = this; this.background = new background(); // fire game loop this.ticker = setinterval(function () { self.tick(); }, 1000 / 60); }

by using self variable, inner function gets access this.

javascript oop prototype