using System; class LambdaArgumentsTest { void M1() { var l1 = (int x) => x + 1; l1(1); var l2 = (int x, int y = 1) => x + y; l2(2, 3); l2(4); l2(5, 6); var l3 = (params int[] x) => x.Length; l3(); l3(7, 8, 9); } delegate int MyDelegate(int x, int y); void M2() { MyDelegate sum = (int x, int y) => x + y; sum(y: 4, x: 5); } }