字母数字组合排序 VB程序

Private Sub Command1_Click()
Dim y As String, b As String, a() As String
s = Trim(Text1.Text)
k = Len(s)
For i = 1 To k
x = Mid(s, i, 1)
t = UCase(x)
If t >= "A" And t <= "Z" Then
y = y + x
Else
b = b + x
End If
Next i
Text2.Text = y
Text3.Text = b
s = Trim(Text2.Text)
k = Len(s)
ReDim a(1 To k)
For i = 1 To k
a(i) = Mid(s, i, 1)
Next i
t = a(1): m = a(1)
For i = 1 To k - 1
If t > a(i) Then
t = t
Else
t = a(i)
End If
Next i
For i = 1 To k
If m < a(i) Then
m = m
Else
m = a(i)
End If
Next i
Print "最大字母为:"; t; "最小字母为;"; m
End Sub
如果满意的话就给加几分吧.....................................

最大最小的依据是什麽?ASCII吗?

用for循环并借助mid函数进行逐位检测即可