/// <summary>
/// Problem 10.
/// Create a List<Student> with sample students. Select only the students that are from group number 2.
/// Use LINQ query. Order the students by FirstName.
/// Implement the previous using the same query expressed with extension methods.
/// </summary>
public static List <Student> FindStudentsGroupTwo(this List <Student> input)
{
return(LinqAndLambdaQueries.FindStudentsGroupTwo(input));
}
/// <summary>
/// Problem 18.
/// Create a program that extracts all students grouped by GroupName and then prints them to the console.
/// Use extension methods.
/// </summary>
public static List <Student> GroupByGrooupNames(this List <Student> input)
{
return(LinqAndLambdaQueries.GroupByGroupName(input));
}
static void Main(string[] args)
{
// test Problem 1. StringBuilder.Substring
Console.WriteLine("\nProblem 1. StringBuilder.Substring");
Console.WriteLine("------------------------------------");
StringBuilder str = new StringBuilder();
str.Append("aaaaaaaabbbbbbbbbbbbbccccccccccccc");
Console.WriteLine("Original string is: {0}", str);
Console.WriteLine("Substring is: {0}", str.SubString(0, 8));
// test Problem 2. IEnumerable extensions
Console.WriteLine("\nProblem 2. IEnumerable extensions");
Console.WriteLine("------------------------------------");
Console.Write("Input values: ");
int[] ints = new int[] { 1, 2, 3, 4, 5, 6 };
foreach (var item in ints)
{
Console.Write(item + " ");
}
Console.Write("\nSum: " + ints.SumExt <int>());
Console.Write("\nProduct: " + ints.ProductExt <int>());
Console.Write("\nMin: " + ints.MinExt <int>());
Console.Write("\nMax: " + ints.MaxExt <int>());
Console.WriteLine();
Student[] students = new Student[]
{
new Student {
FirstName = "Peter", LastName = "Petrov", Age = 18, Tel = "0888123456", Email = "*****@*****.**", FN = 121205,
GroupStudent = new Group(1, "Mathematics"), Marks = new List <double> {
2, 3, 4, 5
}
},
new Student {
FirstName = "Ivan", LastName = "Ivanov", Age = 15, Tel = "0888123457", Email = "*****@*****.**", FN = 155405,
GroupStudent = new Group(1, "Phisycs"), Marks = new List <double> {
6, 6, 6, 6
}
},
new Student {
FirstName = "Atanas", LastName = "Ivanov", Age = 22, Tel = "0888827364", Email = "*****@*****.**", FN = 432106,
GroupStudent = new Group(2, "Mathematics"), Marks = new List <double> {
4, 2, 2, 6
}
},
new Student {
FirstName = "Peter", LastName = "Ivanov", Age = 44, Tel = "003592123456", Email = "*****@*****.**", FN = 152306,
GroupStudent = new Group(2, "Phisycs"), Marks = new List <double> {
2, 2, 2, 2
}
}
};
// test Problem 3. First before last
Console.WriteLine("\nProblem 3. First before last");
Console.WriteLine("------------------------------------");
foreach (var item in LinqAndLambdaQueries.FindFirstBeforeLast(students))
{
Console.WriteLine(item);
}
// test Problem 4. Age range
Console.WriteLine("\nProblem 4. Age range");
Console.WriteLine("------------------------------------");
foreach (var item in LinqAndLambdaQueries.AgeRange(students))
{
Console.WriteLine(item);
}
// test Problem 5. Order students
Console.WriteLine("\nProblem 5. Order students");
Console.WriteLine("------------------------------------");
Console.WriteLine("\nWith lambda");
foreach (var item in LinqAndLambdaQueries.OrderStudentsLambda(students))
{
Console.WriteLine(item);
}
Console.WriteLine("\nWith LINQ");
foreach (var item in LinqAndLambdaQueries.OrderStudentsLinq(students))
{
Console.WriteLine(item);
}
// test Problem 6. Divisible by 7 and 3
int[] numbers = new int[] { 1, 21, 42, 34, 23, 210 };
Console.WriteLine("\nProblem 6. Divisible by 7 and 3");
Console.WriteLine("------------------------------------");
Console.WriteLine("\nWith lambda");
foreach (var item in LinqAndLambdaQueries.FindDivisibleByThreeAndSevenLambda(numbers))
{
Console.Write(item + " ");
}
Console.WriteLine("\nWith LINQ");
foreach (var item in LinqAndLambdaQueries.FindDivisibleByThreeAndSevenLinq(numbers))
{
Console.Write(item + " ");
}
// test Problem 7. Timer
Console.WriteLine();
Console.WriteLine("\nProblem 7. Timer with delegates");
Console.WriteLine("------------------------------------");
Timer timer = new Timer(1);
Timer.MyMethodsDelegate d = delegate() { Console.WriteLine("Timer executed with delegates each 1 second"); };
timer.AddDelegate(d);
timer.Start();
System.Threading.Thread.Sleep(5000);
timer.Stop();
// test Problem 8. Timer with events
Console.WriteLine();
Console.WriteLine("\nProblem 8. Timer with events");
Console.WriteLine("------------------------------------");
TimerEvents timerEv = new TimerEvents(1);
timerEv.RaiseTimerEvent += (sender, e) => { Console.WriteLine("Timer executed with events each {0} second", e.Interval); };
timerEv.Start();
System.Threading.Thread.Sleep(5000);
timerEv.Stop();
List <Student> studentsList = students.ToList <Student>();
// test Problem 9. Students from group number 2
Console.WriteLine("\nProblem 9. Students from group number 2");
Console.WriteLine("------------------------------------");
Console.WriteLine("\nWith LINQ");
foreach (var item in LinqAndLambdaQueries.FindStudentsGroupTwo(studentsList))
{
Console.WriteLine(item);
}
// test Problem 10. Students from group number 2
Console.WriteLine("\nProblem 10. Students from group number 2");
Console.WriteLine("------------------------------------");
Console.WriteLine("\nWith Extension methods");
foreach (var item in studentsList.FindStudentsGroupTwo())
{
Console.WriteLine(item);
}
// test Problem 11. Students with mails in abv.bg
Console.WriteLine("\nProblem 11. Students with mails in abv.bg");
Console.WriteLine("------------------------------------");
foreach (var item in LinqAndLambdaQueries.ExtractAllMails(studentsList))
{
Console.WriteLine(item);
}
// test Problem 12. Students with phones in Sofia
Console.WriteLine("\nProblem 12. Students with phones in Sofia");
Console.WriteLine("------------------------------------");
foreach (var item in LinqAndLambdaQueries.ExtractAllWithPhonesInSofia(studentsList))
{
Console.WriteLine(item);
}
// test Problem 13. Students with at least one mark 6
Console.WriteLine("\nProblem 13. Students with at least one mark 6");
Console.WriteLine("------------------------------------");
LinqAndLambdaQueries.ExtractStudentsMarks(studentsList);
// test Problem 14. Students with exactly two marks 2
Console.WriteLine();
Console.WriteLine("\nProblem 14. Students with exactly two marks 2");
Console.WriteLine("------------------------------------");
foreach (var item in studentsList.ExtractExactlyTwoMarks())
{
Console.WriteLine(item);
}
// test Problem 15. Students that enrolled in 2006
Console.WriteLine();
Console.WriteLine("\nProblem 15. Students that enrolled in 2006");
Console.WriteLine("------------------------------------");
foreach (var item in LinqAndLambdaQueries.ExtractAllWithFNin2006(studentsList))
{
Console.WriteLine(item);
}
// test Problem 16. Students from gorup Mathematics
Console.WriteLine();
Console.WriteLine("\nProblem 16. Students from gorup Mathematics");
Console.WriteLine("------------------------------------");
List <Group> grList = new List <Group>();
grList.Add(new Group(1, "Mathematics"));
foreach (var item in LinqAndLambdaQueries.ExtractStudentGroups(studentsList, grList))
{
Console.WriteLine(item);
}
// test Problem 17. Longest string
Console.WriteLine();
Console.WriteLine("\nProblem 17. Longest string");
Console.WriteLine("------------------------------------");
List <string> strings = new List <string> {
"123", "1234", "12345", "1"
};
Console.WriteLine("Longest string is: " + LinqAndLambdaQueries.StringWithMaxLen(strings));
// test Problem 18. Group by GroupName - LINQ
Console.WriteLine();
Console.WriteLine("\nProblem 18. Group by GroupName - LINQ");
Console.WriteLine("------------------------------------");
foreach (var item in LinqAndLambdaQueries.GroupByGroupName(studentsList))
{
Console.WriteLine(item);
}
// test Problem 19. Group by GroupName - Extension methods
Console.WriteLine();
Console.WriteLine("\nProblem 19. Group by GroupName - Extension methods");
Console.WriteLine("------------------------------------");
foreach (var item in studentsList.GroupByGrooupNames())
{
Console.WriteLine(item);
}
// test Problem 20. Convergent series
Console.WriteLine();
Console.WriteLine("\nProblem 20. Convergent series");
Console.WriteLine("------------------------------------");
Console.WriteLine("1 + 1/2 + 1/4 + 1/8 + 1/16 + …");
Console.WriteLine(Convergent.ConvergentSum(index => 1 / Math.Pow(2, index - 1), 0.01));
Console.WriteLine("1 + 1/2 - 1/4 + 1/8 - 1/16 + …");
Console.WriteLine(Convergent.ConvergentSum(index =>
{
if ((index % 2) == 0)
{
return(1 / Math.Pow(2, index - 1));
}
else
{
return((1 / Math.Pow(2, index - 1)) * -1);
}
}, 0.01));
}
