Delegatlar, lambda va hodisalar

Public Delegate Function Amal(a As Integer, b As Integer) As Integer

Module Dastur
    Function Qoshish(a As Integer, b As Integer) As Integer
        Return a + b
    End Function

    Function Kopaytirish(a As Integer, b As Integer) As Integer
        Return a * b
    End Function

    Sub Main()
        Dim bajar As Amal

        bajar = AddressOf Qoshish
        Console.WriteLine(bajar(6, 7))

        bajar = AddressOf Kopaytirish
        Console.WriteLine(bajar(6, 7))
    End Sub
End Module

Module Dastur
    Sub Main()
        Dim kvadrat As Func(Of Integer, Integer) = Function(x) x * x
        Dim yigindi As Func(Of Integer, Integer, Integer) =
            Function(a, b) a + b
        Dim chiqar As Action(Of String) =
            Sub(matn) Console.WriteLine($">> {matn}")

        Console.WriteLine(kvadrat(9))
        Console.WriteLine(yigindi(15, 27))
        chiqar("salom")
    End Sub
End Module

Module Dastur
    Sub Main()
        Dim sonlar() As Integer = {5, 12, 8, 23, 16}

        Dim juftlar = sonlar.Where(Function(s) s Mod 2 = 0)
        Console.WriteLine(String.Join(", ", juftlar))

        Dim ikkilangan = sonlar.Select(Function(s) s * 2)
        Console.WriteLine(String.Join(", ", ikkilangan))

        Dim jami = sonlar.Sum(Function(s) s)
        Console.WriteLine(jami)
    End Sub
End Module

Module Dastur
    Sub Main()
        Dim baho As Func(Of Integer, String) =
            Function(ball)
                If ball >= 90 Then
                    Return "A'lo"
                ElseIf ball >= 70 Then
                    Return "Yaxshi"
                Else
                    Return "Qoniqarsiz"
                End If
            End Function

        For Each b As Integer In New Integer() {95, 78, 55}
            Console.WriteLine($"{b} -> {baho(b)}")
        Next
    End Sub
End Module

Module Dastur
    Sub Ishlov(sonlar() As Integer, qoida As Func(Of Integer, Boolean),
               nom As String)
        Dim mos = sonlar.Where(qoida)
        Console.WriteLine($"{nom}: {String.Join(", ", mos)}")
    End Sub

    Sub Main()
        Dim sonlar() As Integer = {4, 17, 8, 23, 15, 42}

        Ishlov(sonlar, Function(s) s Mod 2 = 0, "Juftlar")
        Ishlov(sonlar, Function(s) s > 20, "Yiriklar")
        Ishlov(sonlar, Function(s) s < 10, "Kichiklar")
    End Sub
End Module

Module Dastur
    Sub Main()
        Dim chegara As Integer = 10
        Dim sonlar() As Integer = {4, 17, 8, 23}

        Dim tekshir As Func(Of Integer, Boolean) = Function(s) s > chegara
        Console.WriteLine(String.Join(", ", sonlar.Where(tekshir)))

        chegara = 20
        Console.WriteLine(String.Join(", ", sonlar.Where(tekshir)))
    End Sub
End Module

Public Class Hisob
    Public Event QoldiqKamaydi(qoldiq As Decimal)

    Private _qoldiq As Decimal

    Public Sub New(boshlangich As Decimal)
        _qoldiq = boshlangich
    End Sub

    Public Sub Yechish(summa As Decimal)
        _qoldiq -= summa
        Console.WriteLine($"Yechildi: {summa}, qoldiq: {_qoldiq}")

        If _qoldiq < 100000D Then
            RaiseEvent QoldiqKamaydi(_qoldiq)
        End If
    End Sub
End Class

Module Dastur
    Sub Ogohlantir(qoldiq As Decimal)
        Console.WriteLine($"  DIQQAT: qoldiq juda kam - {qoldiq}")
    End Sub

    Sub Main()
        Dim h As New Hisob(500000D)
        AddHandler h.QoldiqKamaydi, AddressOf Ogohlantir

        h.Yechish(200000D)
        h.Yechish(250000D)
    End Sub
End Module

Public Class Tugma
    Public Event Bosildi(nom As String)

    Public Property Nom As String

    Public Sub New(nom As String)
        Me.Nom = nom
    End Sub

    Public Sub Bosish()
        RaiseEvent Bosildi(Nom)
    End Sub
End Class

Module Dastur
    Sub Main()
        Dim t As New Tugma("Saqlash")

        AddHandler t.Bosildi,
            Sub(nom) Console.WriteLine($"Jurnal: {nom} bosildi")
        AddHandler t.Bosildi,
            Sub(nom) Console.WriteLine($"Ekran: {nom} ishga tushdi")

        t.Bosish()
    End Sub
End Module