public static void SortByFirstAndLastName(Student[] students)
{
var result = students.OrderByDescending(x => x.firstName)
.ThenByDescending(y => y.lastName);
foreach (var student in result)
{
Console.WriteLine(student.firstName + " " + student.lastName);
}
}
static void Main(string[] args)
{
Student[] students = new Student[]
{new Student("Alfa", "Betov", 24),
new Student("Boris", "Aleksandrov", 28),
new Student("Dimana", "Nikolova", 20),
new Student("Nikola", "Dimov", 19),
new Student("Dimo", "Dimov", 18)
};
Console.WriteLine("Students list:");
Console.WriteLine(StudentsHelper.StudentsToStirng(students));
Console.WriteLine();
//Write a method that from a given array of students finds all students whose first name is before its last name alphabetically.
Student[] studentsFirstIsBeforeLast = StudentsHelper.FindStudentsWhichFirstNameIsBeforeLast(students);
Console.WriteLine("Students whose first name is before its last name alphabetically");
Console.WriteLine(StudentsHelper.StudentsToStirng(studentsFirstIsBeforeLast));
Console.WriteLine();
//Write a LINQ query that finds the first name and last name of all students with age is between 18 and 24.
Console.WriteLine("First name and last name of all students with age between 18 and 24");
var studentsBetuween18and24Names = students.Where(student => student.Age >= 18 && student.Age <= 24)
.Select(student => new { student.FirstName, student.LastName });
foreach (var item in studentsBetuween18and24Names)
{
Console.WriteLine(item);
}
Console.WriteLine();
//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.
Console.WriteLine("students sorted by first name and last name in descending order(lambda expressions):");
var orderedStudents = students.OrderByDescending(student => student.FirstName).ThenByDescending(student => student.LastName);
foreach (var item in orderedStudents)
{
Console.WriteLine(item);
}
Console.WriteLine("students sorted by first name and last name in descending order(LINQ):");
var orderedStudentsLINQ = from student in students
orderby student.FirstName descending, student.LastName descending
select student;
foreach (var item in orderedStudentsLINQ)
{
Console.WriteLine(item);
}
}
static void Main()
{
Student[] students = new Student[] { new Student("Ivan", "Ivanov", 19),
new Student("Petur", "Stamatov", 21),
new Student("Petur", "Ivanov", 17),
new Student("Iva", "Avramova", 24),
new Student("Greta", "Petrova", 26) };
//task 3
var FirstNameBeforeLastNameAlphabetically = //thumbs up for the variable name :D
from student in students
where student.FirstName.CompareTo(student.LastName) < 0
select student;
Console.WriteLine("First Name is before Last Name alphabetically : ");
foreach (var item in FirstNameBeforeLastNameAlphabetically)
{
Console.WriteLine(item.FirstName + " " + item.LastName);
}
//task 4
Console.WriteLine("Students age is between 18 and 24 : ");
var StudentsWithAgeBetween18and24 =
from student in students
where student.Age >= 18 && student.Age <= 24
select student;
foreach (var item in StudentsWithAgeBetween18and24)
{
Console.WriteLine(item.FirstName + " " + item.LastName);
}
//task 5
Console.WriteLine("Sorted by FirstName and Last Name Lambda : ");
var SortedStudentsFirstNameLastNameDescendingLambda =
students.OrderByDescending(x => x.FirstName).ThenByDescending(x => x.LastName);
foreach (var item in SortedStudentsFirstNameLastNameDescendingLambda)
{
Console.WriteLine(item.FirstName + " " + item.LastName);
}
Console.WriteLine("Sorted by FirstName and Last Name Linq : ");
var SortedStudentsFirstNameLastNameDescendingLINQ =
from student in students
orderby student.FirstName descending, student.LastName descending
select student;
foreach (var item in SortedStudentsFirstNameLastNameDescendingLINQ)
{
Console.WriteLine(item.FirstName + " " + item.LastName);
}
}
static void Main()
{
Student[] students = new Student[] {new Student("Ivan","Ivanov",19) ,
new Student("Petur", "Stamatov" , 21),
new Student("Petur", "Ivanov" , 17),
new Student("Iva" ,"Avramova" , 24),
new Student ("Greta","Petrova" , 26)};
//task 3
var FirstNameBeforeLastNameAlphabetically = //thumbs up for the variable name :D
from student in students
where student.FirstName.CompareTo(student.LastName) < 0
select student;
Console.WriteLine("First Name is before Last Name alphabetically : ");
foreach (var item in FirstNameBeforeLastNameAlphabetically)
{
Console.WriteLine(item.FirstName + " " + item.LastName);
}
//task 4
Console.WriteLine("Students age is between 18 and 24 : ");
var StudentsWithAgeBetween18and24 =
from student in students
where student.Age >= 18 && student.Age <= 24
select student;
foreach (var item in StudentsWithAgeBetween18and24)
{
Console.WriteLine(item.FirstName + " " + item.LastName);
}
//task 5
Console.WriteLine("Sorted by FirstName and Last Name Lambda : ");
var SortedStudentsFirstNameLastNameDescendingLambda =
students.OrderByDescending(x => x.FirstName).ThenByDescending(x => x.LastName);
foreach (var item in SortedStudentsFirstNameLastNameDescendingLambda)
{
Console.WriteLine(item.FirstName + " " + item.LastName);
}
Console.WriteLine("Sorted by FirstName and Last Name Linq : ");
var SortedStudentsFirstNameLastNameDescendingLINQ =
from student in students
orderby student.FirstName descending, student.LastName descending
select student;
foreach (var item in SortedStudentsFirstNameLastNameDescendingLINQ)
{
Console.WriteLine(item.FirstName + " " + item.LastName);
}
}
static void Main(string[] args)
{
int n = int.Parse(Console.ReadLine());
Student[] student = new Student[n];
for (int i = 0; i < n; i++)
{
string[] array = Console.ReadLine().Split(' ', StringSplitOptions.RemoveEmptyEntries).ToArray();
student[i] = new Student(array[0], array[1], double.Parse(array[2]));
}
student = student.OrderByDescending(x => x.Grade).ToArray();
foreach (var person in student)
{
Console.WriteLine(person.ToString());
}
}
static Student[] OrderedByNamesLambda(Student[] inArray)
{
var ordered = inArray.OrderByDescending(student => student.FirstName).ThenByDescending(student => student.LasttName);
return ordered.ToArray();
}
static void Main()
{
Student[] students = new Student[] { new Student("Maria", "Ignatova", 18),
new Student("Ivo", "Argirov", 22),
new Student("Ivo", "Milushev", 21),
new Student("Iva", "Stoykova", 23),
new Student("Miroslav", "Tsankov", 30),
new Student("Nayden", "Sitov", 23) };
//task 3 - Write a method that from a given array of students finds all students whose first name is before its last name alphabetically.
var names =
from name in students
where name.FirstName.CompareTo(name.LastName) == -1
select name;
Console.WriteLine("Students whose first name is before their last name alphabetically: ");
Console.WriteLine();
foreach (var n in names)
{
Console.WriteLine(n.FirstName + " " + n.LastName);
}
Console.WriteLine(new string('-', 40));
Console.WriteLine();
//tast 4 - Write a LINQ query that finds the first name and last name of all students with age between 18 and 24.
var ages =
from age in students
where age.Age >= 18 && age.Age <= 24
select age;
Console.WriteLine("The students between 18 and 24 years are: ");
Console.WriteLine();
foreach (var a in ages)
{
Console.WriteLine("{0} {1} - {2} years old.", a.FirstName, a.LastName, a.Age);
}
Console.WriteLine(new string('-', 40));
Console.WriteLine();
//task 5 - 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.
Console.WriteLine("Students sorted by first and last name (Lambda) : ");
var sortedStudentsDescending =
students.OrderByDescending(x => x.FirstName).ThenByDescending(x => x.LastName);
foreach (var item in sortedStudentsDescending)
{
Console.WriteLine(item.FirstName + " " + item.LastName);
}
Console.WriteLine();
Console.WriteLine("Students sorted by first and last name (Linq) : ");
var sortedStudentsDescendingLINQ =
from student in students
orderby student.FirstName descending, student.LastName descending
select student;
foreach (var item in sortedStudentsDescendingLINQ)
{
Console.WriteLine(item.FirstName + " " + item.LastName);
}
Console.WriteLine(new string('-', 40));
Console.WriteLine();
}
