(function(){

    var body = document.getElementsByTagName("body")[0];

​

    function Question(question, choices, correctAns) {

        this.question = question;

        this.choices = choices;

        this.correctAns = correctAns;

    }

​

    Question.prototype.checkAns = function(givenAns){

        if (this.correctAns === givenAns) {

            console.log("OK");

        }

    };

​

    function Quiz() {

        this.questions = [];

    }

​

    Quiz.prototype.showAllQuestions = function(){

        this.questions.forEach(function(questions){

            console.log(questions.question);

        });

    };

​

    Quiz.prototype.showQuiz = function(){

        this.questions.forEach(function(questions){

​

            for (var i=0; i < questions.choices.length; i+=1) {

                body.innerHTML("OK");

            }

​

        });

    };

​

    var q1 = new Question("What is red?", ["Color", "Animal", "Building"], 1);

    var q2 = new Question("Which music is most popular?", ["Latin", "Pop", "Rock"], 2);

    var quiz = new Quiz();

​

    quiz.questions.push(q1);

    quiz.questions.push(q2);

    quiz.showAllQuestions();

​

​

})();