Question

我遇到了一个编译错误：否则，如果没有If并且我不确定为什么。

Dim product As String

    Do Until product = "P" Or product = "p"
    product = Left(InputBox("Please enter product number", "Product please", "Enter product number here"), 1)
        If product = "P" Or product = "p" Then MsgBox "Thank you"
        ElseIf product = "Enter product number here" Then Exit Sub
        Else: MsgBox "Please enter a valid product number"
        End If
    Loop

Answer 1

由于您的If语句要复杂一些，所以只需“如果此条件为真，就做一件事”，则应将条件与操作分开放在自己的行中：

Dim product As String

Do Until product = "P" Or product = "p"
    product = Left(InputBox("Please enter product number", "Product please", "Enter product number here"), 1)

    If product = "P" Or product = "p" Then 
         MsgBox "Thank you"
    ElseIf product = "Enter product number here" Then 
         Exit Sub
    Else
         MsgBox "Please enter a valid product number"
    End If
Loop

正如我在评论中指出的那样，如果您运行此代码，则ElseIF条件将永远不会发生，并且将陷入无限循环。

Answer 2

考虑一下逻辑流程-将IF放在同一行后第一个MsgBox之后会发生什么。使用F8进入下面的代码以找出答案。干杯！

Sub test()

    Dim product As String

    Do Until product = "P" Or product = "p"
        product = Left(InputBox("Please enter product number", "Product please", "Enter product number here"), 1)
        If product = "P" Or product = "p" Then
            MsgBox "Thank you"
            ElseIf product = "Enter product number here" Then Exit Sub
            Else: MsgBox "Please enter a valid product number"
        End If
    Loop

End Sub

不明白为什么我会遇到编译错误

2 个答案: