$(document).ready(function(){
      var num = 5239;
      var i = 0;
        for(i ; i < 10000; i++){
        num = newNumber(num);
        console.log(num);
        if(num == 1){
            alert("it's happy number");
          break;
        }
      }
      alert("it's not happy number");
 });

function newNumber(num){
  var sum = 0;
  var temp = 0;
  while(num!=0){
    temp = num%10;
    num = (num-temp)/10;
    sum +=  temp*temp;
  }
  return sum;
}