Kaprekars Constant

JavaScript

function KaprekarsConstant(num) { 

  // code goes here  
  var input;
  var anum,dnum,result,iteration;
  for(var x=1;result!==6174;x++){
  debugger;
      if(x===1){ 
          input = num;
      }
      else{
          input = result;
      }
  anum = input.toString().split('').sort().join('');
  dnum = input.toString().split('').sort(function(a, b){return b-a}).join('');
  result = Math.abs(parseInt(dnum) - parseInt(anum));
  iteration = x;
  }
  //alert(anum + " " + dnum + " " +result);
  return iteration; 
         
}
   
// keep this function call here 
alert(KaprekarsConstant(3524));