c# Array.FindAllIndexOf which FindAll IndexOf

Question

I know c# has Array.FindAll and Array.IndexOf.

Is there a Array.FindAllIndexOf which returns int[]?

Answer 1

Searches for an element that matches the conditions defined by the specified predicate, and returns all the zero-based index of the occurrence within the entire System.Array.

public static int[] FindAllIndex(this T[] array, Predicate match)
{
    return array.Select((value, index) => match(value) ? index : -1)
            .Where(index => index != -1).ToArray();
}