VB6 Copy Listbox to Another Listbox – copy or move all list items of one list box to another list box

The most common known way to move all the items of one listbox to another is through the use of a loop like so:

That method is fine and there is nothing wrong with it but if you are interested, many don’t know there is an API to transfer all the items of one listbox to another and this method also prevents duplicates into the second, destination listbox:

At the top of the module: