使用case語句任務檢查的Visual Basic選擇

Question

想知道我爲我的visual basic計算作業做了什麼是正確的。我們的活動任務：

「活動：使用等級選擇Case語句

簡介：

您將使用一個case語句，將允許用戶輸入一個等級值作爲一個整數值，並返回級爲一個字母，從A到E

選擇邏輯

• 如果輸入的號碼是91-100的輸出之間將A

• 如果輸入的號碼是81和90之間的輸出會是B

• 如果輸入的號碼是71和80之間的輸出將是C

• 如果輸入的數是61和輸出70之間將是D

• 如果輸入的號碼是51和60之間的輸出將通過電子郵件

  任何下50是失敗
  任何高於100是不正確的值，他們將不得不再次運行該程序。
  創建必要的變量
  創建必要輸出告訴用戶節目的目的 創建代碼在用戶的名字讀
  創建在等級讀取作爲整數值的代碼
  創建代碼根據上述標準生成相關等級。
  創建必要的輸出代碼輸出用戶的名字和他們的字母」的字母等級

我的代碼：

Module Module1 

Sub Main() 
    Dim anum As Integer 
    Dim name As String 
    Console.WriteLine("This programme converts marks into grades") 
    Console.WriteLine("Please enter name...") 
    name = Console.ReadLine 
    Console.WriteLine("Please enter number of marks...") 
    anum = Console.ReadLine() 
    Select Case anum 
     Case 91 To 100 
      Console.WriteLine(name & " receives an A.") 
     Case 81 To 90 
      Console.WriteLine(name & " receives a B.") 
     Case 71 To 80 
      Console.WriteLine(name & " receives a C.") 
     Case 61 To 70 
      Console.WriteLine(name & " receives a D.") 
     Case 51 To 60 
      Console.WriteLine(name & " receives an E.") 
     Case Is <= 50 
      Console.WriteLine(name & ", unfortunately failed.") 
     Case Is > 100 
      Console.WriteLine(name & ", this is an incorrect value. Please try again.") 
    End Select 
End Sub 

End Module 

將感謝，如果有人可以只確認它是正確或者告訴我，如果我做錯了或需要補充的東西！

感謝。

Answer 1

我會做不同的比你原來的代碼的唯一的事情是： 使用「案例否則」取代您的最終案例聲明中的「Case Is> 100」。 這樣，如果有人輸入了數字以外的其他東西，它會處理一個錯誤。 良好的工作和祝你好運！

Answer 2

原始代碼似乎沒事就在我已經使用了正確的數據類型改進它，加上基本的異常鑄件，並試圖把事情簡單化：

Module Module1 

' Store ranges and chars 
ReadOnly TupleList As New List(Of Tuple(Of Short, Short, Char)) From { _ 
     Tuple.Create(51S, 60S, "E"c), _ 
     Tuple.Create(61S, 70S, "D"c), _ 
     Tuple.Create(71S, 80S, "C"c), _ 
     Tuple.Create(81S, 90S, "B"c), _ 
     Tuple.Create(91S, 100S, "A"c) _ 
} 

' Set custom strings formatting 
ReadOnly str_OK As String = "{0}, receives an {1}." 
ReadOnly str_FAIL As String = "{0}, unfortunately failed." 
ReadOnly str_INCORRECT As String = "{0}, this is an incorrect value. Please try again." 

Sub Main() 

    ' Initialize user variables with a default value (0) 
    Dim anum As Short = 0 
    Dim name As String = 0 

    Console.WriteLine("This programme converts marks into grades") 
    Console.WriteLine("Please enter name...") 
    name = CStr(Console.ReadLine) 

    Try 
     Console.WriteLine("Please enter number of marks...") 
     anum = CShort(Console.ReadLine()) 

    Catch ex As FormatException 
     Console.WriteLine("Please enter a valid number...") 
     Environment.Exit(1) ' Exit from application returning an error exitcode 

    Catch ex As Exception 
     Console.WriteLine(String.Format("{0}: {1}", _ 
             ex.Message, _ 
             ex.StackTrace)) 
     Environment.Exit(1) ' Exit from application returning an error exitcode 

    End Try 

    Select Case anum 

     Case Is <= 50 
      Console.WriteLine(String.Format(str_FAIL, name)) 

     Case Is >= 101 
      Console.WriteLine(String.Format(str_INCORRECT, name)) 

     Case Else ' User value is inside an accepted range 
      For Each Item As Tuple(Of Short, Short, Char) In TupleList 
       If (anum >= Item.Item1 AndAlso anum <= Item.Item2) Then 
        Console.WriteLine(String.Format(str_OK, name, Item.Item3)) 
        Environment.Exit(0) ' Exit from application 
        ' Exit For 
       End If 
      Next Item 

    End Select 

    Environment.Exit(1) ' Exit from application returning an error exitcode 
    ' (When Is <= 50 or Is >= 101) 

End Sub 

End Module