using System;

using System.Linq.Expressions;

​

public class Program

{

    public static void Main()

    {

        Console.WriteLine("****************** C# Equivalent Output **************************\n\n");

        Employee e = new Employee();

        object objEmp = e as object;

        if(objEmp is Employee)

        {

            Console.WriteLine("It is an Empoyee object");

        }

        else

        {

            Console.WriteLine("It is not an Empoyee object");

        }

        Console.WriteLine("\n\n***************** Expression Tree Output **************************\n\n");

​

        TypeBinaryExpression testCondition = Expression.TypeIs(

            Expression.Constant(objEmp),

            typeof(Employee));

​

​

        var ifTrueBlock = WriteLineExpression("It is an Empoyee object");

        var ifFalseBlock = WriteLineExpression("It is not an Empoyee object");

        var ifThenExpr = Expression.IfThenElse(testCondition, ifTrueBlock, ifFalseBlock);

​

        Expression.Lambda<Action>(ifThenExpr).Compile()();

    }

    public static Expression WriteLineExpression(string s)

    {

        return Expression.Call(null,

            typeof(Console).GetMethod("WriteLine", new Type[] { typeof(String) }),

            Expression.Constant(s));

    }

}

​

public class Employee

{

    public string Name { get; set; }

    public DateTime BirthDate { get; set; }

}

​