function show() {
        let date_ = new Date();
    
        let sec = String(date_.getSeconds());
        fill_gaps(sec);
    
        function fill_gaps(candidate) {
            if (candidate.length < 2) {
            candidate = "0" + candidate;
          } else {
          candidate = candidate;
         }
       }
    
        time_ = String(`${sec}`);
        console.log(time_)
      }
The fill_gaps() function is supposed to change the var sec value; but it isn't changing the value outside the function. My guess is that it is not changing on global scope.
I know this is a basic problem but I can't figure it out as I am still a beginer.
Expected:
console.log(time_) = 0("and the current second")
Actual:
console.log(tiem_) = ("the current second")
 
     
    