IndexOutOfRangeException in pinging application

[Reapism]

I am having an exception when running the function PingTest() in terms of the array I'm using. I'm not entirely sure how this is happening. Here is all the code.

    Dim pingTo As String = "www.google.com"
    Dim amountOfTests As Integer = 10
    Dim testIterations(amountOfTests - 1) As Integer

    Public Function AverageOfTests() As Boolean
        Dim average As Double
        For count As Integer = 0 To amountOfTests
            average = average + testIterations(count)
            count += 1
        Next
        txtResults.Text += average

        Return True
    End Function

    Public Function PingTest() As Boolean
        For count As Integer = testIterations(count) To amountOfTests
            count += 1
            Dim ping As New System.Net.NetworkInformation.Ping
            Dim ms = ping.Send(pingTo).RoundtripTime()
            txtResults.Text += System.Environment.NewLine
            txtResults.Text += "pinged (" & pingTo & ") at " & ms & "."
            testIterations(count) = CInt(ms)

        Next
        AverageOfTests()
        Return True
    End Function

    Private Sub btnStart_Click(sender As Object, e As EventArgs) Handles btnStart.Click
        txtResults.Clear()
        PingTest()
    End Sub

[.paul.]

Try this:

For count As Integer = 0 To amountOfTests - 1

[TnTinMN]

Typically, you do not modify the indexing variable (count) within the For-Next block.
Remove

count += 1

from the For-Next blocks or change to one of the Do loop constructs.

[.paul.]

Typically, you do not modify the indexing variable (count) within the For-Next block.
Remove

count += 1

from the For-Next blocks or change to one of the Do loop constructs.

Didn't spot that...

[Reapism]

I get an error under the AverageOfTests() function

Error:
System.IndexOutOfRangeException

The error occurs on the line
average = average + testIterations(count)

New code:

    Dim pingTo As String = "www.google.com"
    Dim amountOfTests As Integer = 10
    Dim testIterations(amountOfTests - 1) As Integer

    Public Function AverageOfTests() As Boolean
        Dim average As Double
        For count As Integer = 0 To amountOfTests
            average = average + testIterations(count)
            count += 1
        Next
        txtResults.Text += average

        Return True
    End Function

    Public Function PingTest() As Boolean
        For count As Integer = 0 To amountOfTests - 1
            count += 1
            Dim ping As New System.Net.NetworkInformation.Ping
            Dim ms = ping.Send(pingTo).RoundtripTime()
            txtResults.Text += System.Environment.NewLine
            txtResults.Text += "pinged (" & pingTo & ") at " & ms & "."
            testIterations(count) = CInt(ms)

        Next
        AverageOfTests()
        Return True
    End Function

Also for this, I need a value to increment to stop it at some point. What would be the correct way to do that?

Typically, you do not modify the indexing variable (count) within the For-Next block.
Remove

count += 1

from the For-Next blocks or change to one of the Do loop constructs.

[.paul.]

change:

For count As Integer = 0 To amountOfTests - 1
    average = average + testIterations(count)
Next

in your AverageOfTests function

and remove:

count += 1

from your PingTest code

[Reapism]

I removed the count += 1. Why do I have to? Does it automagically increment by 1?

change:

For count As Integer = 0 To amountOfTests - 1
    average = average + testIterations(count)
Next

in your AverageOfTests function

and remove:

count += 1

from your PingTest code

[Reapism]

Also

        Dim response As String = InputBox("Enter an IP address or website.")
        If Len(response) > 0 Then
            If response.Contains("http://") Then
                MsgBox("Please enter a valid website address.")
                pingTo = "www.google.com"
                
            Else
                response.Replace("http://", Nothing)
                response.Replace("https://", Nothing)
                
            End If
        Else
        End If

Also, the contains ("https://") executes even though the string doesn't contain it.

EDIT I FIXED MY LOGICAL ERROR.

[.paul.]

for x as integer = 1 to 5
    msgbox(x.ToString)
next

5 msgboxes will pop up one after another... 1,2,3,4,5
The for next block increments itself.

[Reapism]

OH, thanks for explaining that bit.

for x as integer = 1 to 5
    msgbox(x.ToString)
next

5 msgboxes will pop up one after another... 1,2,3,4,5
The for next block increments itself.