Question

I don’t know whats wrong with this:

      var get_depth = function(item, depth) {
        if(item.parent_id !== null) {
          get_depth(get_item_by_id(item.parent_id),depth+1);
        } else {
          alert ("return: " + depth);
          return depth;
        }
      };

The alert message always throws a correct depth but the variable where i want to have the value stored in only accept one iteration (return value = 1) after two or more iterations the value of my variable is undefined. I do not understand that.

Answer 1

That’s because you should return the value each time :

 var get_depth = function(item, depth) {
        if(item.parent_id !== null) {
          return get_depth(get_item_by_id(item.parent_id),depth+1);
        } else {
          alert ("return: " + depth);
          return depth;
        }
      };