/* Get Programming with JavaScript

 * Listing 12.07

 * Checking quiz answers

 */

​

var getQuiz = function () {

  var score = 0,

      qIndex = 0,

      inPlay = true,

      questions,

      next,

      getQuestion,

      checkAnswer,

      submit;

  questions = [

    {

      question: "What is the highest mountain in the world?",

      answer: "Everest"

    },

    {

      question: "What is the highest mountain in Scotland?",

      answer: "Ben Nevis"

    }

  ];

  next = function () {

    qIndex = qIndex + 1;

    if (qIndex >= questions.length) {

      inPlay = false;

      console.log("You have finished the quiz.");

    }

  };

  getQuestion = function () {

    if (inPlay) {

      return questions[qIndex].question;

    } else {

      return "You have finished the quiz.";

    }

  };

  checkAnswer = function (userAnswer) {

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

      console.log("Correct!");

      score = score + 1;

    } else {

      console.log("No, the answer is " + questions[qIndex].answer);

    }

  };

  submit = function (userAnswer) {

    var message = "You have finished the quiz.";

    if (inPlay) {

      checkAnswer(userAnswer);

      next();

      message = "Your score is " + score + " out of " + qIndex;

    }

    return message;

  };

  return {

    quizMe: getQuestion,

    submit: submit

  };

};

​

var quiz = getQuiz();

​

​

​

/* Further Adventures

 *

 * 1) Run the program.

 *

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

 *    quiz.submit methods.

 *    

 *    > quiz.quizMe()

 *      What is the highest mountain in the world?

 *    > quiz.submit("K2")

 *

 * 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

 *    };

 *

 */