vb如何用if语句实现百分制成绩向优良等级转换？变量怎样声明。

假如变量是分数a 输出框是text1 代码如下 If a>=80 Then text1.text=“优秀” ElseIf a<60 Then text1.text=“不及格” Else text1.text=“及格” End If 其实这运用到了分支结构.由于我是用手机发的.所以要把代码中的双引号改成英语双引号. 希望能对您有帮助!好运!

Dim A As Single, I As Byte
Dim B As String
Dim C(0 To 3) As String
Dim Num As Boolean

Private Sub Form_Load()
Form1.AutoRedraw = True
C(0) = "优秀"
C(1) = "良好"
C(2) = "及格"
C(3) = "不及格"
Do
B = InputBox("请输入0--100之间的数字(结束--回车)", "输入成绩")
If B = "" Then Exit Do
For I = 1 To Len(B)
If (Asc(Mid(B, I, 1)) < 48 Or Asc(Mid(B, I, 1)) > 57) And Asc(Mid(B, I, 1)) <> 46 Then
Num = False
Exit For
Else
Num = True
End If
Next
If Num Then
A = Val(B)