Rendezvous.OnlyEvens

Program.cs

using System.Text;

IEnumerable<int> onlyEvens(IEnumerable<int> list) => list.Where(i => i % 2 == 0).OrderBy(i => i);

void Dump(IEnumerable<int> list)
{
	var sb = new StringBuilder();
	sb.Append("[");
	sb.Append(string.Join(", ", list.Select(i => i.ToString())));
	sb.Append("]");
	Console.WriteLine(sb.ToString());
}

Dump(onlyEvens(new[] { 1, 2, 3, 4, 5, 2}));
Dump(onlyEvens(new[] { 7, 8, 1, 0, 2, 5 }));
Dump(onlyEvens(new[] { 11, 13, 15 }));