给定整数n(n>3),判断它是不是素数(技术循环)

Private Sub Command1_Click()
n = 5
For j = 2 To n - 1
If n Mod j = 0 Then Exit For
Next j
If j = n Then
Print n & "是素数"
Else
Print n & "不是素数"
End If
End Sub

Function isprime(Num As Long) As Boolean
If Num < 2 Then isprime = False: Exit Function

Dim i As Long

For i = 2 To Sqr(Num)
If (Num Mod i) = 0 Then
isprime = False
Exit Function
End If
Next i

isprime = True
End Function