Find the lowest set bit

Question

I have 5 bit numbers like

10000
01000
00100

If only one bit is on in my calculation i have no problem.

but if 2 bits are on then I

Answer 1

function isolateLowestBit(input)
{
  mask = 1;
  while (mask <= input)
  {
    if (mask & input)
    {
      // found match - mask is set to the value of the lowest bit
      return mask;
    }

    mask *= 2;  // shift up mask by one bit
  }

  // no match
  return 0;
}

Beware that bitwise operations in Javascript are a bad idea, since since Javascript numbers aren't naturally integer.