FunctionalMethods.cs

using System;

namespace Recipes.LINQ.R0102
{
    public class FunctionalMethods
    {
        public static void Main()
        {
            // Functional method f(x) and g(x):
            Func<int, int> f = x => x + 1;
            Func<int, int> g = x => x + 2;

            // Compound functional method f(g(x)):
            Func<Func<int, int>, Func<int, int>, int, int> fog = (f1, g1, x) => f1.Invoke(g1.Invoke(x));

            Console.WriteLine();
            // Computing f(x) with x = 2:

            Console.WriteLine("f(2) = {0}", f(2));
            Console.WriteLine("g(3) = {0}", g(3));
            Console.WriteLine("f(g(5) = {0}", fog(f, g, 5));

            Console.WriteLine();
        }
    }
}