How to delete multiple entries from a List without going out of range?

Question

I have a list of integers that contains a number of values (say, 200).

List<int> ExampleList;

And another list on integers that holds the indexes that need to be deleted from ExampleList. However, this list is not sorted.

List<int> RemoveFromExampleList;

If it were sorted, I would have run a reverse loop and deleted all the values like this:

for (int i = (RemoveFromExampleList.Count-1); i >=0; i--)
{
    ExampleList.RemoveAt(RemoveFromExampleList[i]);
}

Do I have to sort RemoveFromExampleList, or is there another way to prune the unnecessary values from ExampleList?

If I do have to sort, whats the easiest way to sort? Is there any inbuilt C# library/method to sort?

Answer 1

If RemoveFromExampleList is a list of indexes, you would have to sort it and work in descending order to delete based on those indexes. Doing it any other way would cause you to delete values you don't mean to delete.

Answer 2

Here is the one liner.

ExampleList.RemoveAll(x => RemoveFromExampleList.Contains(ExampleList.IndexOf(x)));