/* Get Programming with JavaScript

 * Listing 13.16

 * Using an IIFE with the quiz app

 */

​

var quiz = (function () {

  var qIndex = 0;

  var questions = [

    { question: "7 x 8", answer: "56" },

    { question: "12 x 12", answer: "144" },

    { question: "5 x 6", answer: "30" },

    { question: "9 x 3", answer: "27" }

  ];

  var getQuestion = function () {

    qIndex = between(0, questions.length - 1);

    return questions[qIndex].question;

  };

  var checkAnswer = function (userAnswer) {

    if (userAnswer === questions[qIndex].answer) {

      return "Correct!";

    } else {

      return "No, the answer is " + questions[qIndex].answer;

    }

};

  return {

    quizMe: getQuestion,

    submit: checkAnswer

  };

})();

​

​

​

​

/* Further Adventures

 *

 * 1) Run the program.

 *

 * 2) Take the quiz, using the quiz.quizMe and

 *    quiz.submit methods.

 *    

 *    > quiz.quizMe()

 *      12 x 12

 *    > quiz.submit("144")

 *

 * 3) Add some more questions and answers, run the

 *    program and take the quiz again.

 *

 * CHALLENGE:

 *

 * 4) Add a hint property for each question.

 *

 * 5) Define a getHint function that returns

 *    the hint for the current question.

 *

 * 6) Add a helpMe property to the public interface,

 *    the object returned by getQuiz. The getHint

 *    function should be assigned to the

 *    helpMe property.

 *

 *    return {

 *      quizMe: getQuestion,

 *      submit: submit,

 *      helpMe: getHint

 *    };

 *

 */