public static void Main()
{
Student pesho = new Student("Pesho", "Peshev", "213400","032555555","*****@*****.**", 1);
Student ivan = new Student("Ivan", "Ivanov", "213406","03255555","*****@*****.**", 2);
Student kina = new Student("Kina", "Kinova", "213806","029999999","*****@*****.**", 1);
Student pina = new Student("Pina", "Pinova", "213490","0266666","*****@*****.**", 2);
pesho.Marks.Add(2);
pesho.Marks.Add(2);
ivan.Marks.Add(6);
kina.Marks.Add(6);
List<Student> students= new List<Student>();
students.Add(pesho);
students.Add(ivan);
students.Add(kina);
students.Add(pina);
//Problem 9. Student groups
Console.WriteLine();
Console.WriteLine("Students from group 2 (Linq) ");
var studentGroup =
from student in students
where student.GroupNumber == 2
orderby student.FirstName
select student;
foreach (var student in studentGroup)
{
Console.WriteLine(student.FirstName);
}
Console.WriteLine("Students from group 2 (Extension m): ");
//Problem 10. Student groups extensions
//Implement the previous using the same query expressed with extension methods.
var studentsGroup2 = students.SelectByGroup();
foreach (var student in studentsGroup2)
{
Console.WriteLine(student.FirstName);
}
Console.WriteLine();
/* Problem 11. Extract students by email
Extract all students that have email in abv.bg.
Use string methods and LINQ.
*/
var studentsEmailAbv =
from student in students
where student.Email.Contains("@abv.bg")
select student;
foreach (var item in studentsEmailAbv)
{
Console.WriteLine(item.FirstName);
}
/* Problem 12. Extract students by phone
Extract all students with phones in Sofia.
Use LINQ.
* */
var studentsPhoneSofia =
from student in students
where student.PhoneNumber.StartsWith("02") || student.PhoneNumber.StartsWith("+3592")
select student;
//Problem 13. Extract students by marks
//Select all students that have at least one mark Excellent (6) into a new anonymous class that has properties – FullName and Marks.
//Use LINQ.
var studentsExcellent =
from student in students
where student.Marks.Contains(6)
select new { FullName = student.FirstName + " " + student.LastName, Marks = student.Marks };
foreach (var student in studentsExcellent)
{
Console.WriteLine(student.FullName);
}
//Problem 14. Extract students with two marks
//Write down a similar program that extracts the students with exactly two marks "2".
//Use extension methods.
var studentsGroup3 = students.ExtractTwoMarks();
Console.WriteLine("Students with exactly two marks 2:");
foreach (var student in studentsGroup2)
{
Console.WriteLine(student.FirstName);
}
Console.WriteLine();
//Problem 15. Extract marks
//Extract all Marks of the students that enrolled in 2006. (The students from 2006 have 06 as their 5-th and 6-th digit in the FN).
var students2006 =
from student in students
where student.FN.Substring(4,2)=="06"
select student.Marks;
foreach (var item in students2006)
{
foreach (var mark in item)
{
Console.WriteLine(mark);
}
}
//Problem 17. Longest string
//Write a program to return the string with maximum length from an array of strings.
//Use LINQ.
string[] stringsArray = { "bla", "blabla", "blablabla" };
string max = stringsArray.OrderByDescending(s => s.Length).First();
Console.Write("Longest string: ");
Console.WriteLine(max);
//Problem 18. Grouped by GroupNumber
//Create a program that extracts all students grouped by GroupNumber and then prints them to the console.
//Use LINQ.
Console.WriteLine(" With Linq");
Console.WriteLine();
var result = students.OrderBy(st => st.GroupNumber);
foreach (var student in result)
{
Console.WriteLine("{0}, Group: {1}",student.FirstName,student.GroupNumber);
}
Console.WriteLine();
Console.WriteLine("With extension");
Console.WriteLine();
//Using Extensions
var resultWithExtensions = students.OrderByGroupNumber();
foreach (var resultWithExtension in resultWithExtensions)
{
Console.WriteLine("{0}, Group: {1}", resultWithExtension.FirstName, resultWithExtension.GroupNumber);
}
}
public StudentRO(Student source)
{
_source = source;
}
