// finds the first name and last name of all students with age between 18 and 24.
public static string[] AgeRange(Student[] students)
{
string[] result = students
.Where(student => student.Years >= 18 && student.Years <= 24)
.Select(student => String.Format("{0}\t{1}", student.FirstName, student.LastName))
.ToArray();
return result;
}
// from students[] finds all students whose first name is before its last name alphabetically.
public static Student[] FirstBeforeLastName(Student[] students)
{
Student[] returnStudents = students.Where(s => s.FirstName.CompareTo(s.LastName) < 0).ToArray();
return returnStudents;
}
