這是我必須交給的任務。我錯過了一些關於函數計算的內容

Question

我有三個測試分數，最低分數將被丟棄。函數用於計算最終成績，而成績必須從數字轉換爲字母。我已盡我所能，我試圖弄清楚並確保函數的寫入是正確的。

'I put these at public class so they could be used throughout the program 

Dim test1 As Double 
Dim test2 As Double 
Dim test3 As Double 
Dim student As String 
Dim Result1 As String 
Dim total As String 


Function SemesterGrade(ByVal t1 As Double, ByVal t2 As Double, ByVal t3 As Double) As Double 

    'This function determines the test scores and drops the lowest score from calculation 
    If t1 < t2 And t1 < t3 Then 
     total = CStr(((t2 + t3)/2)) 

    ElseIf t2 < t3 And t2 < t1 Then 
     total = CStr(((test1 + test3)/2)) 

    ElseIf t3 < t2 And t3 < t1 Then 
     total = CStr(((t1 + t2)/2)) 

     'I added this if statement to calculate if all the scores were the same because the program would not give me the correct output 
    ElseIf t1 = t2 And t2 = t3 Then 
     total = CStr((t1 + t2 + t3)/3) 

    End If 

    'this returns the result from this function 
    Return CDbl(total) 



End Function 

Private Sub btnDetermine_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDetermine.Click 
    Dim result As String 
    'these pull the information from my textboxes 
    test1 = CDbl(txtFirst.Text) 
    test2 = CDbl(txtSecond.Text) 
    test3 = CDbl(txtThird.Text) 
    student = txtName.Text.ToUpper 

    'this is how i use the function calculation 
    result = CStr((SemesterGrade(test1, test2, test3))) 

    'This is to convert the number score to a letter 
    If CDbl(total) >= 90 Then 
     Result1 = ("A") 
    ElseIf CDbl(total) >= 80 Then 
     Result1 = "B" 
    ElseIf CDbl(total) >= 70 Then 
     Result1 = "C" 
    ElseIf CDbl(total) >= 60 Then 
     Result1 = "D" 
    ElseIf CDbl(total) < 60 Then 
     Result1 = "F" 

    End If 

    'This is the output for the result 
    txtResult.Text = student & ": " & Result1 


End Sub 

End Class 

Answer 1

問題是，你正在調用你的函數變成一個變量，並比較另一個變量。更換下面的部分並重試;

'this is how i use the function calculation 
result = (SemesterGrade(test1, test2, test3)) 

'This is to convert the number score to a letter 
If result >= 90 Then 
    Result1 = ("A") 
ElseIfresult >= 80 Then 
    Result1 = "B" 
ElseIf result >= 70 Then 
    Result1 = "C" 
ElseIf result >= 60 Then 
    Result1 = "D" 
ElseIf result < 60 Then 
    Result1 = "F" 
End If