/*Using the extension methods OrderBy() and ThenBy() with lambda expressions sort the
* students by first name and last name in descending order. Rewrite the same with LINQ.
---------------------------------------------------------------------------------------------------------*/
private static Student[] OrderByNameLINQ(Student[] students)
{
var result =
from student in students
orderby student.FirstName descending, student.FamilyName descending
select student;
return result.ToArray();
}
/*Write a LINQ query that finds the first name and last name of
* all students with age between 18 and 24.*/
private static IEnumerable SelectStudentsByAge(Student[] students)
{
var result =
from student in students
where student.Age >= 18 && student.Age <= 24
select student.FirstName + ' ' + student.FamilyName;
return result;
// return students.Where(x => (x.Age >= 18 && x.Age <= 24)).Select(x => x.FirstName + ' ' + x.FamilyName);
}
/*Write a method that from a given array of students finds all students whose
* first name is before its last name alphabetically. Use LINQ query operators.*/
private static Student[] SelectStudentsByNames(Student[] students)
{
var result =
from student in students
where student.FirstName.CompareTo(student.FamilyName) < 0
select student;
return result.ToArray();
// return students.Where(x => (x.FirstName.CompareTo(x.FamilyName) < 0)).ToArray();
}
private static Student[] OrderByNameLambda(Student[] students)
{
return students.OrderByDescending(x => x.FirstName).ThenByDescending(y => y.FamilyName).ToArray();
}