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JavaScript JavaScript Loops, Arrays and Objects Tracking Multiple Items with Arrays Build a Quiz Challenge, Part 1

Posted by Marina Shumeyko
Marina Shumeyko
5,647 Points

I did it. Horaaay!!! Any feedbacks ?

/*
1. Ask questions
2. Store answers
3. Compare user answer with quiz answer
4. If answer is right:
    - save it to the variable "correctAnswer";
    - print the question;
5. If answer is wrong:
    - print the question;
*/

// use to print message
function print(message) {
  document.write(message);
}

//ask question
function askQuestion(question) {
     answer = prompt(question);
     return answer.toLowerCase();
}

//Create array with questions and answers 
var quiz = [
    ['What is the capital of Denmark?', 'copenhagen'],
    ['What are we learning now?', 'javascript'],
    ['Do you like to write code', 'yes']
];
var correctAnswer = 0;
var question;
var quizAnswer;

// Print the result
function printResult(arr) {
    var correctListHtml = '<h2>You got these question(s) correct:</h2> <ol>';
    var wrongListHtml = '<h2>You got these question(s) wrong:</h2> <ol>';

// Compare user answer with quiz answer
    for (var i = 0; i < arr.length; i++) {
        question = arr[i][0];
        quizAnswer = arr[i][1];

        if (askQuestion(question) === quizAnswer) {
            correctAnswer++;
            correctListHtml += '<li>' + question + '</li>';
        } else {
            wrongListHtml += '<li>' + question + '</li>';
        }
    }

    correctListHtml += '</ol>';
    wrongListHtml += '</ol>';


    print('You got ' + correctAnswer + ' question(s) right');
    print(correctListHtml);
    print(wrongListHtml);
}

printResult(quiz);
Mark Wilkowske
Mark Wilkowske
Courses Plus Student 18,131 Points
Mark Wilkowske
Mark Wilkowske
Courses Plus Student 18,131 Points

Nice work, Marina! One idea I had and put in my CodePen was this
wrongListHtml += '<li>' + question + ' ' + quizAnswer + ' </li>';

Maybe you want the user to see the answer to a question they got wrong? And how would you color the answer text green?

2 Answers

Tom Lawrence
Tom Lawrence
8,685 Points
Tom Lawrence
Tom Lawrence
8,685 Points

looks good, here is how i did it. 

function print(message) {
  document.write(message);
}

function runQuiz(questions)
{
  var correctAnswers = 0;
  for(var i = 0; i < questions.length; i++)
  {
    var question = questions[i];
    var userAnswer = prompt(question[0]);
    var answerCorrect = checkAnswer(question, userAnswer);
    answerCorrect === true ? correctAnswers++ : correctAnswers = correctAnswers;
  }
  return correctAnswers;
}

function checkAnswer(question, answer)
{
  if(question[1] === answer)
    return true;
  return false;
}


//start here
var questions = 
    [
      ['my name', 'tom'],
      ['my age', 'unknown'],
      ['my city', 'newcastle']
    ];

var correctAnswers = runQuiz(questions);
print(correctAnswers + ' correct');
Marina Shumeyko
Marina Shumeyko
5,647 Points

Hi Tom. Nice work. I made refactoring in your example, hope it is ok. The main points is:

  • no need to create variables, which are do the same work. Try to keep your code simple as much as possible for others. A lot of variables are sometimes can confuse. I was learned about it from JS developers, who's reviewing my code at work.
function print(message) {
    document.write(message);
}

function runQuiz(questions) {
    var correctAnswers = 0;

    for(var i = 0; i < questions.length; i++) {
        var userAnswer = prompt(questions[i][0]);
        var answerCorrect = checkAnswer(questions[i][1], userAnswer);

        answerCorrect === true ? correctAnswers++ : correctAnswers;
    }
    return correctAnswers;
}

function checkAnswer(question, answer) {
     return (question === answer) ? true : false;
}

var questions = [
    ['my name', 'tom'],
    ['my age', 'unknown'],
    ['my city', 'newcastle']
];

print(runQuiz(questions) + ' correct');
Tom Lawrence
Tom Lawrence
8,685 Points
Tom Lawrence
Tom Lawrence
8,685 Points

I don't mind, it looks good! always interesting to see how others write the same code.