C# Extract list of fields from list of class

Question

I've got a list of elements of a certain class. This class contains a field.

class Foo {public int i;}
List<Foo> list;

I'd like to extract the field from all items in the list into a new list.

List<int> result = list.ExtractField (e => e.i); // imaginary

There are surely multiple ways to do that, but I did not find a nice-looking solution yet. I figured linq might help, but I was not sure how exactly.

Answer 1

Just:

List<int> result = list.Select(e => e.i).ToList();

or

List<int> result = list.ConvertAll(e => e.i);

The latter is more efficient (because it knows the final size to start with), but will only work for lists and arrays rather than any arbitrary sequence.