using System;

using System.Linq;

using System.Linq.Expressions;

public class Student 

{

    public int StudentID { get; set; }

    public string StudentName { get; set; }

    public int Age { get; set; }

}

​

public class Program

{

    public static void Main()

    {

        var stud =  new Student(){ StudentID = 1, StudentName = "Steve", Age = 20};     

        Func<Student, bool> isTeenager = s=> s.Age > 12 && s.Age < 20;

        Console.WriteLine(isTeenager(stud));

        Expression<Func<Student, bool>> isTeenExpr = s=> s.Age > 12 && s.Age < 20;

        Console.WriteLine(isTeenExpr.Compile()(stud));

    }

}