Private Sub Command1_Click()
Dim x As Integer, y As Long, st As String
For x=100 To 1000
y=x^2
st=Str(x) & Str(y)
If Then ‘①
List1. AddItem"x: "& Str(x) & "x2: "&Str(y) &"x&y: "& Str(st)
End If
Next x
End Sub
Private Function judge(s As String) As Boolean
Dim a(1 To 100) As String
For i=1 To Len(s)
a(i) =Mid(s, i, 1)
Next i
For i =1 To Len(s)-1
For j=i+ 1 To Len(s)
If Then Exit Function. ‘②
Next j
Next i
Judge=True
End Function