How to convert list of objects with two fields to array with one of them using LINQ

Question

It's hard for me to explain, so let me show it with pseudo code:

ObjectX
{
    int a;
    string b;
}
List<ObjectX> list = //some list of objectsX//
int [] array = list.Select(obj=>obj.a);

I want to fill an array of ints with ints from objectsX, using only one line of linq.

Answer 1

You were almost there:

int[] array = list.Select(obj=>obj.a).ToArray();

you need to just add ToArray at the end

Answer 2

The only problem in your code is that Select returns IEnumerable.

Convert it to an array:
int[] array = list.Select(obj=>obj.a).ToArray();