摘要:VB學習心得2.迴圈
參考書籍:Visual Basic 2008程式設計學習教本
1.撰寫一支程式,呼叫10次MsgBox,嘗試輸出10行的Hello Visual Basic
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
Dim callthing As String = "Hello Visual Basic"
Dim varint As Integer = 0
For varint = 0 To 9
MsgBox(callthing)
TextBox1.Text = CStr(varint) + "." + callthing
Next
End Sub
End Class
6.撰寫一支程式,讓使用者選擇加總的起始與結束值,進行指定範圍內的加總
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
Dim topnum As String = TextBox1.Text
Dim endnum As String = TextBox2.Text
Dim varint As Integer = 0
Dim varint2 As Integer = 0
For varint = CInt(topnum) To CInt(endnum)
varint2 += varint
Next
Label1.Text = CStr(varint2)
End Sub
End Class
10.利用巢狀迴圈輸出以下結果
1
12
123
1234
12345
123456
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
Dim n1 As Integer
Dim n2 As Integer
Dim s As String
For n1 = 1 To 6
For n2 = 1 To n1
s = s & n2
'用一個字串承接數字'
Next
s = s + vbNewLine
Next
TextBox1.Text = s
End Sub
End Class
為何s = s & n2不用s=s+n2
4-16有說明,由於數字跟字串用+會出現錯誤,vb本身會無視,結果會直接跑完迴圈
11.利用巢狀迴圈輸出以下結果
1
22
333
4444
55555
666666
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
Dim n1 As Integer
Dim n2 As Integer
Dim s As String
For n1 = 1 To 6
For n2 = 1 To n1
s = s & n1
Next
s = s + vbNewLine
Next
TextBox1.Text = s
End Sub
End Class
這段 s = s & n1主要在於巢狀迴圈6-14頁有提到
外部迴圈跑完一圈時,會等內部迴圈跑完在繼續跑
12.請利用巢狀式迴圈,輸出九九乘法
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim n1 As Integer
Dim n2 As Integer
Dim n3 As String
For n1 = 1 To 9
For n2 = 1 To 9
n3 = n3 & n1 & "*" & n2 & "=" & (n1 * n2) & " " & " "
Next
n3 = n3 + vbNewLine
Next
TextBox1.Text = n3
End Sub
End Class
