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JavaScript

Posted by Evan Bean
Evan Bean
Courses Plus Student 4,145 Points

Why did I need extra parentheses to make the .toUpperCase() method work?

I got my quiz program to function and it even matched Dave's solution, minus variable names and such, pretty closely. However, I had trouble getting my comparisons to work. It kept resulting in "incorrect" answers (even when they were correct) until I added a second set of parentheses around the variable and method, like this: (firstQ.toUpperCase()). When I only had firstQ.toUpperCase(), the conditional always went to the else clause.

Did I do something wrong so that I needed to add those extra parentheses?

Including one of my question code blocks as a sample:

// First Question var firstQ = prompt('What is the capital of Denmark?'); if ((firstQ.toUpperCase()) === 'COPENHAGEN') { questionsLeft -= 1 alert('That\'s right! ' + questionsLeft + ' questions left!'); answer += 1; } else { questionsLeft -= 1 alert('Sorry, that\'s wrong. ' + questionsLeft + ' questions left!'); }

1 Answer

Abraham Juliot
Abraham Juliot
47,353 Points

Hi Evan,

In this case, no. You are fine without the extra parenthesis. Although, using parenthesis can provide readibility for a group of expressions, it's only necessary to specify operator precedence.

In your code, you may need to include semicolons after both instances of questionsLeft -= 1 .

Evan Bean
Evan Bean
Courses Plus Student 4,145 Points

Thanks, Abraham. The semicolons were the missing factor. I missed them when I wrote the code block for the first question and repeated the error by copying the block for each of the following questions.

Yes, I know I should have been fine without the extra parentheses. I didn't ask if I needed them. I asked why. As I said in my original post, I had to add those to make the program run properly, and I didn't know why. Now I know it was those missing semicolons.

Thanks for the help.