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

John Barhorst
John Barhorst
9,648 Points
Posted by John Barhorst
John Barhorst
9,648 Points

Why is this "for" loop running through my prompt()'s 3 times?

I'm not looking for much more than why my "for" function is popping up my prompt() dialogues nine times instead of just 3.

I'm using the following:

var quizQuestions = [
 ["How many licks does it take?", "3"],
 ["Why so serious?", "the batman"],
 ["Where's the beef?", "wendy's"]
];

var correctAnswers = 0;

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


for ( var i = 0; i < quizQuestions.length; i += 1) {
   var question1 = prompt(quizQuestions[0][0]);
   var question2 = prompt(quizQuestions[1][0]);
   var question3 = prompt(quizQuestions[2][0]);
  }

I'm just working through how I want to do this quiz challenge yet, so if I'm not even taking the right approach I'd like to figure that out on my own. My issue here is that in trying to test my code the prompts are looping through 3 times for each question, even though using quizQuestions.length in the JavaScript console on Chrome tells me that it is only 3 long.

At first I thought the count might change since I'm using arrays within arrays ( feints within feints! ), but even then wouldn't it end at 6? Shouldn't the counter variable "i" still be adding one each time and ending the 'for' function on the third prompt?

Thanks for reading so far down!

Gilbert Kennen
Gilbert Kennen
10,661 Points

When doing code blocks, you can include the name of the language after the opening backticks and you will get the correct syntax highlighting. For example

```JavaScript

// JavaScript code here.

```

2 Answers

Gilbert Kennen
Gilbert Kennen
10,661 Points

Your for loop is set up correctly, it is running its code block 3 times. The problem is that each time it runs it is running 3 prompt() methods. What you want is something that looks more like this:

var quizQuestions = [ 
  ["How many licks does it take?", "3"], 
  ["Why so serious?", "The Batman"], 
  ["Where's the beef?", "Wendy's"] 
];

for ( var i = 0; i < quizQuestions.length; i += 1 ) {
  var answer = prompt(quizQuestions[i][0]);
  // code to do something based on the result of answer
}

This for loop runs three times and the value of i will be 0 on the first run, 1 on the second run and 2 on the third run, so it will prompt each of your questions once.

John Barhorst
John Barhorst
9,648 Points
John Barhorst
John Barhorst
9,648 Points

Ah yeah! That clears it up nicely. Thanks a lot :D