Ndtyjky

I have a public variable Public AssetFamilyCollection As New Collection which is a collection of the classe AssetFamily I've created.

Within a sub, I create an AssetFamily instance with Dim familyChosen As AssetFamily.
Then when I've identified the AssetFamily I want in the collection I do Set familyChosen = AssetFamilyCollection(i)

At some point, I make changes on familyChosen property and I noticed that those changes have also been done to AssetFamilyCollection(i)

I thought familyChosen was a private variable, a copy from AssetFamilyCollection(i) and only exists inside the sub. Apparently not.

Why the public and private variable are impacted by the changes and not the private one in the sub ?

Thanks !

No it doesn't work like that.

The variable familyChosen is actually a reference to the same object as the array element is referring.

So you can modify that object either through that reference or through the array element.

• 
  

  This is the problem about the Basic Type and the Object Type.

  
  
  

  You may need to know the diffenerce between the Deep Copy and
  Shallow Copy.

  
  

• 
  

  When the code "Dim familyChosen As AssetFamily" executed, a new
  “AssetFamily” was created.

  
  
  

  But, when "Set familyChosen = AssetFamilyCollection(i)" executed,
  nothing was created, you just made the familyChosen pointed to the
  “AssetFamily” that already existed.

  
  

• 
  

  So, if you want a "copy" but not a "pointer", you can write a
  function in the class “AssetFamily”, such as “Clone”, to create a new
  "AssetFamily" and make it the same as the old one.

  
  
  

  Then, you can write something like this:

  
  
  

  Set familyChosen = AssetFamilyCollection(i).Clone()

  
  

It's becuase of

Set familyChosen = AssetFamilyCollection(i)

'familyChosen' is now a reference to 'AssetFamilyCollection(i)'

Any changes to one instance will update the other as they are both referencing the same object.