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JavaScript

Posted by David Lindblad
David Lindblad
941 Points

correct += does not seem to be working... I know I'm missing something obvious

/*

  1. Store correct answers
    • When quiz begins, no answers are correct */ let correct = 0;

// 2. Store the rank of a player

let rank;

// 3. Select the <main> HTML element

/*

  1. Ask at least 5 questions
    • Store each answer in a variable
    • Keep track of the number of correct answers */ const q1 = prompt ('Number of fingers?'); if (q1 === 10){ correct += 1; } const q2 = prompt ('Number of toes?'); if (q2 === 10) { correct += 1; } const q3 = prompt ('Number of ears?'); if (q3 === 2) { correct += 1; }

const q4 = prompt ('Number of eyes?'); if (q4 === 2) { correct +=1; }

const q5 = prompt ('Number of mouths'); if (q5 === 1) { correct +=1; }

/*

  1. Rank player based on number of correct answers
    • 5 correct = Gold
    • 3-4 correct = Silver
    • 1-2 correct = Bronze
    • 0 correct = No crown */

if (correct >= 5){ rank = 'Gold'; } else if (correct >=3) { rank = 'Silver'; } else if (correct >=2) { rank = 'Bronze'; } else { rank = '"Giant Loser"'; }

// 6. Output results to the <main> element

alert (Thanks for playing, your ranking is ${rank}, you got ${correct} out of a possible 5);

Raksmey soriya
Raksmey soriya
3,101 Points
Raksmey soriya
Raksmey soriya
3,101 Points

You forgot to convert a correct answer from the prompt. we can covert it by adding + before it or using parseInt();

And here is the answer:)

Store correct answers When quiz begins, no answers are correct */ let correct = 0; // 2. Store the rank of a player

let rank;

// 3. Select the <main> HTML element

/*

Ask at least 5 questions Store each answer in a variable Keep track of the number of correct answers */ const q1 = prompt ('Number of fingers?');if (+q1 === 10){ correct += 1;} const q2 = prompt ('Number of toes?'); if (+q2 === 10) { correct += 1; } const q3 = prompt ('Number of ears?'); if (+q3 === 2) { correct += 1; } const q4 = prompt ('Number of eyes?'); if (+q4 === 2) { correct +=1; } const q5 = prompt ('Number of mouths'); if (+q5 === 1) { correct +=1; }

/*

Rank player based on number of correct answers 5 correct = Gold 3-4 correct = Silver 1-2 correct = Bronze 0 correct = No crown */ if (correct >= 5){ rank = 'Gold'; } else if (correct >=3) { rank = 'Silver'; } else if (correct >=2) { rank = 'Bronze'; } else { rank = '"Giant Loser"'; }

// 6. Output results to the <main> element

alert ( Thanks for playing, your ranking is ${rank}, you got ${correct} out of a possible 5);

David Lindblad
David Lindblad
941 Points

That works thanks, what I don't understand is why that's necessary for numbers but not strings?

5 Answers

David Lindblad
David Lindblad
941 Points

Good to know, thanks. With the strict comparison operator === in my code it was still not adding 1 to 'correct' even when I was using/inputting the expected number, that's what is confusing me... unless I'm still missing something? Sorry, I really am very new to all this.

Steven Parker
Steven Parker
231,153 Points
Steven Parker
Steven Parker
231,153 Points

That's right, with the strict comparison the answer never matched.

Steven Parker
Steven Parker
231,153 Points
Steven Parker
Steven Parker
231,153 Points

The strict (type-sensitive) comparison operator "===" won't consider a string to match a number no matter what the displayed value is. It will compare numbers to numbers, or strings to strings, but not mixed.

There are three ways to handle it:

  • convert the input into a number, as Raksmey suggested
  • compare with a string instead of a number :point_right: if (q1 === "10") { correct += 1; }
  • use the standard comparison operator :point_right: if (q1 == 10) { correct += 1; }
David Lindblad
David Lindblad
941 Points
David Lindblad
David Lindblad
941 Points

I was only wanting it to work if the number input was '10', guess I'm not yet far enough along in the course to understand why the + is required before the 'q1', 'q2' etc for a number but not a string. Thanks

Steven Parker
Steven Parker
231,153 Points
Steven Parker
Steven Parker
231,153 Points

The "+" in front of a string converts it to a number. And quotes around "10" makes it a string.
The standard "==" operator will do conversion for you.

David Lindblad
David Lindblad
941 Points
David Lindblad
David Lindblad
941 Points

Not sure what you mean by the answer never matched, if Iā€™m expecting ... === 10 and entering 10 how does that not match?

Steven Parker
Steven Parker
231,153 Points
Steven Parker
Steven Parker
231,153 Points

The "prompt" function gives back a string, so "q1" had a string in it. When you compare it using "===" to the number 10, it doesn't match because one is a string and the other is a number.

But if you use "==" the system converts for you and they will match.

Glad I could help. You can mark a question solved by choosing a "best answer".
And happy coding!

David Lindblad
David Lindblad
941 Points
David Lindblad
David Lindblad
941 Points

Ah, didn't realize the prompt only returned strings. Thanks Steven.

Steven Parker
Steven Parker
231,153 Points
Steven Parker
Steven Parker
231,153 Points

David Lindblad ā€” Glad to help. But normally, one would choose a "best answer" on the answer the contained the information that helped most to solve the issue! :see_no_evil:

(You can always change that choice :wink:)