Problem Statement

Select certain elements from an Array into a new Array in a generic way.

To demonstrate, select all even numbers from an Array. As an option, give a second solution which filters destructively, by modifying the original Array rather than creating a new Array.

Let's start with the solution:

var array integer: arr is [] (1, 2, 3, 4, 5);
var array integer: evens is 0 times 0;
var integer: number is 0;

for number range arr do
  if not odd(number) then
    evens &:= [] (number);
  end if;
end for;