Perhitungan aritmatika, logika dan perbandingan dengan VB 2008

 Public Class Form2

    Private Sub btnDeskripsi_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDeskripsi.Click
        Dim deskrip, output, inputan As String
        Dim panjang_input, pesan As String
        Dim i As Integer
        If txtInput.Text = "" Then
            MessageBox.Show("Tidak ada data inputan", "Information", MessageBoxButtons.OK, MessageBoxIcon.Information)
            Call hapus()
        ElseIf txtInput.Text <> "" Then
            inputan = txtInput.Text
            panjang_input = Len(txtInput.Text)

            For i = 1 To panjang_input
                deskrip = Mid(inputan, i, 1)
                deskrip = Asc(deskrip)
                deskrip = (deskrip - 20) + 43 ' invert key enkripsi
                deskrip = Chr(deskrip)
                output = output & deskrip
            Next i
            txtOutput.Text = output
            btnEnkripsi.Enabled = False
        End If
    End Sub
    Private Sub btnEnkripsi_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnEnkripsi.Click
        Dim Enkrip, output, inputan As String
        Dim panjang_input As String
        Dim i As Integer
        If txtInput.Text = "" Then
            MessageBox.Show("Tidak ada data inputan", "Information", MessageBoxButtons.OK, MessageBoxIcon.Information)
            Call hapus()
        ElseIf txtInput.Text <> "" Then
            inputan = txtInput.Text
            panjang_input = Len(txtInput.Text)

            For i = 1 To panjang_input
                Enkrip = Mid(inputan, i, 1) ' ambil karakter inputan
                Enkrip = Asc(Enkrip) 'ubah karakter ke ascii
                Enkrip = (Enkrip + 20) - 43 ' invert key deskripsi
                Enkrip = Chr(Enkrip) ' ubah kembali ke karakter
                output = output & Enkrip
            Next i
            txtOutput.Text = output ' tampilkan enkrip
            btnDeskripsi.Enabled = False
        End If
    End Sub
    Private Sub btnClear_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnClear.Click
        Call hapus()
    End Sub
    Private Sub hapus()
        txtInput.Text = ""
        txtOutput.Text = ""
        btnDeskripsi.Enabled = True
        btnEnkripsi.Enabled = True
    End Sub

    Private Sub Form2_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        txtInput.Focus()
    End Sub
End Class


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