Question

VB窗体上包含有两个名称分别为Op1和Op2的单选按钮，标题分别为“100-200的素数和” 和“200-400的素数和”

窗体上包含有两个名称分别为Op1和Op2的单选按钮，标题分别为“100-200的素数和” 和“200-400的素数和”。还有一个文本框和一个命令按钮，标题分别为“求和”。程序运行后，选中某个单选按钮，并单击“求和”按钮，则计算指明范围内的素数之和，并显示在文本框中。

Answer 1

Private Sub Command1_Click()
Dim m%, sum%, i%, tag As Boolean
s = 0
If Option1.Value = True Then
For n = 100 To 200
tag = True
For i = 2 To n - 1
If n Mod i = 0 Then tag = False
Exit For
Next i
If tag = True Then sum = sum + n
Next n
Else
For n = 201 To 400
tag = True
For i = 2 To n - 1
If n Mod i = 0 Then tag = False
Exit For
Next i

If tag = True Then sum = sum + n

Next n
End If
Text1.Text = sum
End Sub

Answer 2

If a Mod b = 0 Then
Exit For
End If
Next b
If a = b Then
sum = sum + a
End If
Next a
Else
For a = 200 To 400
For b = 2 To a - 1
If a Mod b = 0 Then
Exit For
End If
Next b
If a = b Then
sum = sum + a
End If

Next a
End If
Text1.Text = sum

End Sub