You can write JSON into local storage and just use JSON.stringify (non-jQuery) to serialize a JavaScript object. You cannot write to any file using JavaScript alone. Just cookies or local (or session) storage.

var obj = {

    name: 'Dhayalan',

    score: 100

};



localStorage.setItem('gameStorage', JSON.stringify(obj));

And to retrieve the object later, such as on page refresh or browser close/open...

var obj = JSON.parse(localStorage.getItem('gameStorage'));