Small Lists issue
im trying to check if a list remained the same after a prozess:
''' List<string> startList=previousList;
previousList.Add("item");
Console.Writeline(startList==previousList);
'''
This, according to me, should output false since the list was changed. However for some reason the "startList" is also changed simultaniously with the "previousList", eventhough I didn't use ".Add()" with "startList". Why does this happen and how can I fix it?
3 Replies
they point to the same list
This is a general programming thing. Your assignment of
var startList = previousList; only copies the reference to previousList to startList. Both variables will still refer to the same instance of the list.
What you need to do is copy the list. You can do that via var startList = new List<string>(previousList);.
Beyond that, you cannot check list equality by using ==. Lists are reference types and don't implement a custom equality operator, meaning you're simply comparing whether the two variables refer to the same instance. What you need is something like startList.SequenceEquals(previousList).Thank you very much. This helped a lot. Everything works correctly know.