qb64中函数错误所需的数目

Question

我正在编写一个qb64 / QBasic软件程序，将数字等级0-100转换为字母等级(a，b，c，d，f)。我已经设置了它，以便使用字符串/数组来允许输入无限等级。然而，当我试图计算字母等级，并将它用calcGrade!(MyList(Index%))调用回打印时，我会收到错误的“函数所需的数字”，有人能帮我吗？

ReDim MyList(0) As String
Dim Grade 
Dim Index%
_Title "Letter Grade Calculator"
Print "Enter your numerical grades. To finish enter (exit)"
Do While Grade$ <> "exit"
    Input "Enter Grade"; Grade$
    If Grade$ <> "exit" Then
        Index% = Index% + 1
        ReDim _Preserve MyList(Index%)
        MyList(Index%) = Grade$
    End If
Loop
Cls
For Index% = 1 To UBound(MyList)
    Print MyList(Index%);
     Print "Letter Grade:"; calcGrade!(MyList(Index%))
Next Index%
Function calcGrade! (numGrade)
      Select Case val(numGrade)
        Case is > 100
             calcGrade! = "A+"
       Case Is > 90
             calcGrade! = "A"
       Case Is > 80
             calcGrade! = "B"
      Case Is > 70
             calcGrade! = "C"
      Case Is > 60
             calcGrade! = "D"
       Case Is > 50
             calcGrade! = "F"
      Case Else
             calcGrade! = "ERROR: Invalid character"
     End Select
End Function

Answer 1

然而，当我试图计算字母等级并将其拨回用

打印时，我会收到“函数所需的号码”。

您为calcGrade!(MyList(Index%))接收的错误“函数所需的数字”意味着calcGrade函数期望从您那里收到一个数值参数，该参数将分配给它的numGrade参数。

Function calcGrade! (numGrade)

没有任何显式声明，numGrade参数默认为单一数值格式。但是，您正在通过提供一个MyList字符串参数。

另一个错误是函数名称上的感叹号声明函数以返回单个值。因此，您不能将"A+“、"A”、"B“、"C”、"D“、"F”和“错误:无效字符”字符串值分配给它。

解决方案是将$字符串后缀用于Calculate$和numGrade$。

...
Cls
For Index% = 1 To UBound(MyList)
    Print MyList(Index%); " -> ";
    Print "Letter Grade:"; calcGrade$(MyList(Index%))
Next Index%
Function calcGrade$ (numGrade$)
    Select Case val(numGrade$)
      Case Is > 100
             calcGrade$ = "A+"
      Case Is > 90
             calcGrade$ = "A"
      Case Is > 80
             calcGrade$ = "B"
      Case Is > 70
             calcGrade$ = "C"
      Case Is > 60
             calcGrade$ = "D"
      Case Is > 50
             calcGrade$ = "F"
      Case Else
             calcGrade$ = "ERROR: Invalid character"
    End Select