//using lambda predicate public static IEnumerable<Student> SelectByAgeBetween18_24Labda(Student[] arr) { var selected = arr.Where(student => student.Age >= 18 && student.Age <= 24); return selected; }
//using lambda predicate public static IEnumerable<Student> SelectFirstBeforeLastNameLambda(Student[] arr) { var selected = arr.Where(student => student.FirstName.CompareTo(student.LastName) < 0); return selected; }