Check Odd numbers without modulo operator

Question

I am creating a function that returns whether the passed in number is odd Without the modulo operator. The tricky part is that it should work for NEGATIVE numbers and ZERO.

here's my codes so far:

function testodd(num) {
  return (num/2)*2==num;
}

var output = testodd(17);
console.log(output); // --> true

Am I making some mistakes here? Or is there a better way to do this?

Answer 1

you can use Bitwise operator and get same result. does this help.

<script type="text/javascript">
   function oddOrEven(x) {
       return ( x & 1 ) ? "odd" : "even";
   }    
   console.log(oddOrEven(10));
</script>

For more detail about bitwise operator