How to copy List in C#

Question

I want to copy a List of Objects, but i keep getting references between the objects.

List<MyClass> copy = original;

When i change the value in the copy List, the original List ends up modified also. Is there a way to work around it?

Inveigh

check this post: https://mcmap.net/q/497895/-cloning-list-lt-t-gt – Homely

Answer 1

You can do this:

List<MyClass> copy = original.ToList();

This would make an element-by-element copy of the list, rather than copying the reference to the list itself.

Sidewinder

@Inveigh Could you please be more specific about the "not working" part? – Sidewinder

when i changed the value of the copy list, the original list is getting modified too – Inveigh

@Inveigh Right - that's because the copy is shallow. If you add or remove items to/from the original, the copy is not going to "see" that change. However, changing mutable objects inside the list would be reflected in the copy as well. – Sidewinder

would deep copy maintain the value in the original list even if the copy list is modified? – Inveigh

@Inveigh Yes. If you want a deep copy, use List<MyClass> copy = original.Select(v => new MyClass(v)).ToList(); (assuming that MyClass has a "copy constructor" that takes an instance of the same class and returns a "deep copy" of the object). – Sidewinder