Using a Do while loop, sum all the even numbers from 0 to the number entered.

[king_bevo13]

I need help writing a sub that asks the user for a positive integer less than 100. Using a Do While loop sum all the even numbers from 0 to the number entered. Display the results of this calculation in a MsgBox. Assume 0 is an even number. Check to be sure that the number is within the specified range and allow the user to correct the entry if it is not without having to re-run the problem.

 

[Fluff]

Is this homework ?

 

[mumps]

Try:

Sub Test()
    Dim response As String
    Dim x As Long
    Dim y As Long
    y = 0
    Do
      response = InputBox("Please enter a number greater than 0 and less than 100.")
      If response <> "" And response > 0 And response < 100 Then
            For x = 0 To response Step 2
                y = x + y
            Next x
            MsgBox y
            Exit Do
      Else
            MsgBox ("You must enter a number greater than 0 and less than 100.")
      End If
    Loop
End Sub

 

[mumps]

@Fluff: I never thought of that. I posted after seeing your response. Hopefully, it isn't homework!

 

[lrobbo314]

Sub test()

Dim uInput As Integer
Dim Result As Integer
Dim cnt As Integer
Result = 0
cnt = 0
uInput = Application.InputBox("Enter an Even Integer <= 100")
    
    If uInput >= 0 And uInput <= 100 And uInput Mod 2 = 0 Then
        Do While cnt < uInput
            cnt = cnt + 2
            Result = Result + cnt
        Loop
    Else
        MsgBox "Invalid Entry", vbCritical + vbOKOnly
        Exit Sub
    End If
    
MsgBox Result, vbOKOnly
End Sub

 

[Fluff]

@mumps
To me, it just seems a tad odd that the OP is so specific about using a Do While Loop & also a MsgBox

 

[Rick Rothstein]

You do not need to use a loop to calculate the sum of the even numbers from 0 to some given even even number, you can calculate it directly...

[table="width: 500"]
[tr]
	[td]Sub SumEvenNumbers()
  Dim Num As Long
  Num = Application.InputBox("What even number do you want to sum up to?", Type:=1)
  If Num Mod 2 <> 0 Then
    MsgBox "That was not an even number!!!"
  Else
    MsgBox "Sum of even numbers up to " & Num & " = " & [B][COLOR="#0000FF"]Num * (Num + 2) / 4[/COLOR][/B]
  End If
End Sub[/td]
[/tr]
[/table]