How can I use the Math.random() function to randomize a series of test questions?

Question

I wrote a program which asks the user a series of questions and determines whether the answer entered by the user is correct or incorrect. Example:

var questionsCorrect = 0
var question1 = prompt("question 1");
if (question1.toLowerCase() === "answer 1") {
    question1 = true;
    questionsCorrect += 1;
    alert("Correct");
} else {
    question1 = false;
    alert("Incorrect");
}

var question2 = prompt("question 2");
if (question2.toLowerCase() === "answer 2") {
    question2 = true;
    questionsCorrect += 1;
    alert("Correct");
} else {
    question2 = false;
    alert("Incorrect");
}
...

I plan on displaying how many questions the user answered correctly after all of the questions are asked. Suppose the code goes on this way until question10. how would I use the Math.random() function so that the questions are asked in random order?

Possible duplicate of [Generate random number between two numbers in JavaScript](http://stackoverflow.com/questions/4959975/generate-random-number-between-two-numbers-in-javascript) — Tha'er AlAjlouni ثائر العجلوني, Feb 14 '17 at 13:14
maybe it is smarter to learn the concept of function first, to prevent repeating code. then i suggest to have a look to arrays. — Nina Scholz, Feb 14 '17 at 13:15

score 0 · Answer 1 · edited May 23 '17 at 12:16

This can help you get started.

https://jsfiddle.net/wwnzk6z9/1/

Psuedo-code explanation:

Define an array of questions
Shuffle the array using a custom function (source)
Keep track of the current index of the array so that you know which question the test taker should be presented with next and also to know when the test taker is done.
Store the answer in the answer array (not coded).

Code:

var questions = [
  'question 1',
  'question 2',
  'question 3',
  'question 4',
  'question 5',
  'question 6',
  'question 7',
  'question 8',
  'question 9',
  'question 10'
]

shuffle(questions)

var index = 0

// assign to window for jsFiddle. You won't need to do this in your code.
window.question = function() {
  if (index === 10) {
    alert('Complete!')
    return;
  }
  alert(questions[index])
  index++
}

function shuffle(array) {
  var currentIndex = array.length, temporaryValue, randomIndex;

  // While there remain elements to shuffle...
  while (0 !== currentIndex) {

    // Pick a remaining element...
    randomIndex = Math.floor(Math.random() * currentIndex);
    currentIndex -= 1;

    // And swap it with the current element.
    temporaryValue = array[currentIndex];
    array[currentIndex] = array[randomIndex];
    array[randomIndex] = temporaryValue;
  }

  return array;
}

How can I use the Math.random() function to randomize a series of test questions?

1 Answers1