Looping through a Self Referencing Object

Question

I have an object such that it can contain a list of its own type. For example, an items class contains various properties. Another class, ItemSet consists of a list of items but can also have a nested Item set. In other words, an ItemSet can contain other item sets. This looks as follows:

public class Item
{
    public int Property1 { get; set; }
    public int Property2 { get; set; }
    public int Property3 { get; set; }
    public int Property4 { get; set; }
}

public class ItemSet
{
    public List<Item> Items { get; set; }
    //.
    //.
    //.
    //.
    public List<ItemSet> ItemSets { get; set; }



}

I've gone in circles(haha get it?) trying to figure out how to loop through the ItemSet object. I have been unable to adjust for the infinite possibilities of parent and child sets. I feel like i a making this much harder than it needs to be.

ItemSets = getItemSets(....);
bool hasSets = false;
ItemSet currentItemSet;
foreach(ItemSet itemSet in currentItemSets)
{
     currentItemSet = itemSet;
     hasSets = HasSets(currentItemSet);

     if(hasSets == false)
     {
         //do stuff with currentItemSet
     }

     while(hasSets == true)
     {
         List<ItemSet> SubSets = getItemSets(CurrentItemSet);
         foreach(subset in SubSets)
         {
             currentItemSet = subset;
             //do stuff with currentItemSet

             hasSets = HasSets(currentItemSet);


             ??????????????????????????
         }

     }
}

I know im significantly off here but was hoping for some pointers. I do need to be able to discern if the Itemset contains children subsets and handle appropriately.

Possible duplicate of [How to flatten tree via LINQ?](http://stackoverflow.com/questions/11830174/how-to-flatten-tree-via-linq) — Sinatr, Mar 14 '17 at 14:50

Connell.O'Donnell · Answer 1 · 2017-03-14T15:11:06.780

6

Define a method for your ItemSet class that can loop through the sets and recursively call the same method on each of them. Something like this:

class ItemSet
{
    public List<ItemSet> ItemSets { get; set; }
    public bool hasSets { get; set; }

    public void Loop()
    {
        if (hasSets)
        {
            ItemSets.ForEach(s => s.Loop());
        }

        // do stuff here
    }
}

Update

Or just use a recursive method

void Loop(ItemSet set)
{
    set.ItemSets?.ForEach(i => Loop(i));
}

edited Mar 14 '17 at 15:11

answered Mar 14 '17 at 14:49

Connell.O'Donnell

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@Connel.O'Donnell Would it be possible to duplicate this without including the loop on the object itself. I am dealing with legacy code here and the less i change the better. (I would prefer a full rewrite but that is not an option). – LCaraway Mar 14 '17 at 15:03

Looping through a Self Referencing Object

1 Answers1