lecture notes

HW:
Sub Procedures, Part I
question 6, 8, 36, 38, 48-54 even
look at answer to one of the odd questions to get a sense of how to do it.

answer to q 38 for If blocks
If year mod 400 = 0 Then
'leap
ElseIf year mod 100 = 0 Then
' not leap
ElseIf year mod 4 = 0 Then
'leap
Else
' not leap
Endif


' leap year
If year mod 400 = 0 Or (year mod 100 <> 0 And year mod 4 = 0) Then
MsgBox("Leap year!")
MessageBox.Show("Leap year!")
Else
MsgBox("Not a leap year!")
Endif

Write a program that allows the user to use a button to toggle the color of the text in a text box between black and red.
' this will NOT work
If textbox1.ForeColor = Color.Black Then
textbox1.ForeColor = Color.Red
Endif
If textbox1.ForeColor = Color.Red Then
textbox1.ForeColor = Color.Black
Endif

' this WILL work
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        If TextBox1.ForeColor = Color.Black Then
            TextBox1.ForeColor = Color.Red
        Else ' If TextBox1.ForeColor = Color.Red Then
            TextBox1.ForeColor = Color.Black
        End If
    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        TextBox1.ForeColor = Color.Black
    End Sub


    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        TextBox1.Visible = Not TextBox1.Visible
    End Sub

biggest:
Public Class Form1
    Dim biggest As Integer
    Dim secondBiggest As Integer

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim theNum As Integer
        theNum = Val(TextBox1.Text)

        If theNum >= biggest Then
            ' update my maxes
            secondBiggest = biggest
            biggest = theNum
        ElseIf theNum > secondBiggest Then
            secondBiggest = theNum
        End If
      
    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        TextBox1.ForeColor = Color.Black
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        Button2.Text = "Biggest: " & biggest & vbTab & "SecondBiggest: " & secondBiggest
    End Sub
End Class