static void Main(string[] args)
{
Student[] students = new Student[]
{
new Student("Kiro","Asparuhov",19),
new Student("Borislav","Vaptsarov",21),
new Student("Gabriel","Georgiev",21),
new Student("Uknown","Aleksiev",12),
new Student("Filip","Filipov",88)
};
FirstBeforeLastName(students);
AgeComparison(students);
OrderByNameLambda(students);
OrderByNameLinq(students);
//Write a program that prints from given array of integers all numbers that are divisible by 7 and 3. Use the built-in extension methods and lambda expressions. Rewrite the same with LINQ.
int[] intArray = new int[50];
Parallel.For(1, intArray.Length+1, x => intArray[x-1] = x);
var viaLambda = LambdaSelectionNumbers(intArray);
var viaLinq = LinqSelectionNumbers(intArray);
Console.WriteLine("\nLambda - select all numbers that are divisible by 7 and 3 (21) from 1..50 : ");
Console.WriteLine(String.Join(",", viaLambda) + "\n");
Console.WriteLine("LINQ- select all numbers that are divisible by 7 and 3 (21) from 1..50 : ");
Console.WriteLine(String.Join(",", viaLinq) + "\n");
}
//Using the extension methods OrderBy() and ThenBy() with lambda expressions sort the students by first name and last name in descending order.
static void OrderByNameLambda(Student[] students)
{
Console.WriteLine("\nLambda - first name and last name in descending order : ");
var items = students.OrderByDescending(x => x.FirstName).ThenByDescending(y => y.LastName);
foreach (var item in items)
{
Console.WriteLine(String.Format("{0} {1}", item.FirstName, item.LastName));
}
}
/*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.*/
static void FirstBeforeLastName(Student[] array)
{
Console.WriteLine("Students whose first name is before its last name alphabetically : ");
var query = from i in array
where i.FirstName.CompareTo(i.LastName) == -1
select i;
foreach (var item in query)
{
Console.WriteLine(String.Format("{0} {1}", item.FirstName, item.LastName));
}
}
//Write a LINQ query that finds the first name and last name of all students with age between 18 and 24.
static void AgeComparison(Student[] students)
{
Console.WriteLine("\nStudents with age between 18 and 24 : ");
var query = from i in students
where i.Age >= 18 && i.Age <= 24
select i;
foreach (var item in query)
{
Console.WriteLine(String.Format("{0} {1} {2}", item.FirstName, item.LastName,item.Age));
}
}
//Rewrite the same with LINQ.
private static void OrderByNameLinq(Student[] students)
{
Console.WriteLine("\nLinq - first name and last name in descending order : ");
var items = from i in students
orderby i.FirstName descending, i.LastName descending
select i;
foreach (var item in items)
{
Console.WriteLine(String.Format("{0} {1}", item.FirstName, item.LastName));
}
}