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JavaScript JavaScript Arrays Multidimensional Arrays Build a Quiz Challenge – One Solution

Samuel Kleos
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.a{fill-rule:evenodd;}techdegree
Samuel Kleos
Front End Web Development Techdegree Student 13,307 Points

My answers are always wrong.

I just keep getting the prompt "Sorry that's incorrect. Moving on..." even if I answer with the correct answer.

// 1. Create a multidimensional array to hold quiz questions and answers
let questions = [
    ["How many stars in the galaxy", 1],
    ["What's my mums name?", "frank"],
    ["How much of a dum dum are you out of 10?", 10]
];

// 2. Store the number of questions answered correctly
let correct_answers;

/* 
  3. Use a loop to cycle through each question
      - Present each question to the user
      - Compare the user's response to answer in the array
      - If the response matches the answer, the number of correctly
        answered questions increments by 1
*/
for ( let i = 0; i < questions.length; i++ ) {
    let guess = prompt(`Hi there, ${questions[i][0]}`);
    let answer = questions[i][1]

    if ( guess === answer ) {
        alert("Correctamundo!");
        correct_answers++;
    } else {
        alert("Sorry that's incorrect. Moving on...");
    }
}

1 Answer

Steven Parker
Steven Parker
231,261 Points

If you tried the 2nd question, you would have found that it worked, though the other 2 did not. That's because guess is always a string, but on those questions answer is a number. And the type-sensitive comparison operator ( === ) will always consider items of different types to not match, no matter what the contents.

This is easily resolved by either storing the answers as strings in the array, or by using the standard comparison operator ( == ) instead.