Question

//first
if(num % 2 == 0 ) {
  isEven = true;
}


//second
isEven = (num %2 == 0);

What is the best thing to do, and is first case a case of code smell?

Answer 1

They don’t do the same thing – if num is odd, the first leaves isEven with its previous value, the second sets it to false.

I would:

• Try to initialize the variable at the point of declaration, and not change it afterwards.
• Use the second form in preference to the first in general.

When the body of an if block is just setting a variable, and the value can be expressed as some simple modification of the condition of the if block, and you always want to set some value, I would just use the simple assignment.

The same goes for return statements – I would rather have:

return (num % 2 == 0); // Or (num & 1 == 0)

than

if (num % 2 == 0) {
    return true;
} else {
    return false;
}