输入一个正整数(>=2),判断其是否为素数。所谓素数是指除了1和它本身之外,不能被其他数整除的正整数,如2,3,5,7,11等。 方法一: Private Sub Command1_Click() Dim n As Long, isprime As Boolean n = InputBox(" 请输入一个不小于 2 的正整数: ") isprime = True For i = 2 To Sqr(n) If n Mod i = 0 Then isprime = False Exit For End If Next i If isprime Then Print n; " 是素数 " Else Print n; " 不是素数 " End If End Sub 方法二: Private Sub Form_Click() Dim n As Integer n = InputBox(" 请输入一个正整数 (>=2)") k = Int(Sqr(n)) i = 2 swit = 0 While i <= k And swit = 0 If n Mod i = 0 Then swit = 1 Else i = i + 1 End If Wend If swit = 0 Then Print n; " 是一个素数 " Else Print n; " 不是素数 " End If End Sub 方法三: Private Sub Form_Click() Dim n As Integer n = InputBox(" 请输入一个正整数 (>=2)") k = 0 For i = 2 To Sqr(n) ' n-1 或 n/2 或 n\2 If n Mod i = 0 Then k = 1 Next i If k = 0 Then Print n; " 是一个素数 " Else Print n; " 不是素数 " End If End Sub Private Sub Command1_Click() Dim n As Long, i As Integer n = InputBox("请输入一个大于2的正整数") For i = 2 To Sqr(n) If n Mod i = 0 Then Print n; "不是素数!" Exit For ElseIf n Mod i <> 0 And i = Int(Sqr(n)) Then Print n; "是素数!" End If Next i End Sub