invert number mathematically

invert.jl

function invert(num)
  rev = 0
  
  while num >= 10
    
    rev = (rev + num % 10) * 10
    num = fld(num, 10)
  end
  return (rev + num)
end

invert.js

function invert(num) {
  var
    inv = 0;
  
  while ( num >= 10 ) {
    
    inv = (inv + num % 10) * 10;
    num = parseInt(num/10);
  }
  return (inv + num);
}