Private Sub Command1_Click()
Dim n As Integer, i As Integer
Dim s As Integer, x As Integer, f As Boolean
n= Val(Text1.Text)
f= False: s=0
i=2
Do While ①
For x=2 To i\2
If i Mod x=0 Then Exit For ‘Exit For用于退出For循环
Next x
If ② Then
s=s+1
If Then ‘③
Label1.Caption= "第"& Str(n) & "个素数为:"& Str()
f= True
End If
End If
i=i+1
Loop
End Sub
① ②