javascriptreturnconditional-operator

How do I return true or false for ternary operator in Javascript?


I'm trying to convert the code below to a shorthand version with a ternary operator

     if (sum % 10 === 0) {
        return true;
     } else {
        return false;
      }

It works fine as is, but when I change it to

sum % 10 === 0 ? return true : return false; 

I get a syntax error, and when I change it to

sum % 10 === 0 ? true : false; 

it doesn't work as intended.

If anyone can enlighten me as to what's going on, I'd be much appreciated.


Solution

  • What you tried:

    sum % 10 === 0 ? return true : return false; 
    

    This does not work, because return is a statement and not an expression. A statement can not be used inside of an expression.

    sum % 10 === 0 ? true : false; 
    

    This works, but without a return statement, it is just an expression without using it.

    Finally, you need to return the result of the conditional (ternary) operator ?:, like

    return sum % 10 === 0 ? true : false; 
    

    For a shorter approach you could return the result of the comparison without ternary.

    return sum % 10 === 0;