vb中怎么求100到200的素数和？？

Question

一楼的能不能把每一步都说明一下，我才刚学vb ,function函数不是很懂，先谢谢了

Answer 1

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

Private Sub Command1_Click()
Dim i As Long
Dim s As Long

For i = 100 To 200
If isprime(i) Then s = s + i
Next i

Print "100到200的素数和:";s
End Sub

Answer 2

Private Sub Command1_Click()
Dim i As Integer, a As Integer
Dim s As Integer, str As String
Dim b As Boolean
For i = 100 To 200
b = True
For a = 2 To i - 1
If i Mod a = 0 Then
b = False
Exit For
End If
Next a
If b = True Then
s = s + i
End If
Next i
Text1.Text = s
End Sub

Answer 3

vb书上有一个现成的答案
去找来看看吧