How can I output sequence of number in descending order when the first input is higher than the seco-CodePudding

This one is working but it only output a sequence of number in ascending order even if the First Input is higher than the Second Input.

Here is what I want to happen

Ascending Order when

First Input: 2

Second Input: 8

Result 2, 3, 4, 5, 6, 7, 8

Descending Orden when

First Input: 9

Second Input: 6

Result: 9, 8, 7, 6

 Private Sub btnAccept_Click(sender As Object, e As EventArgs) Handles btnAccept.Click
    Dim A = txtstart.Text
    Dim B = txtend.Text

    Dim Start, Ending As Integer

    If A < B Then
        Start = A
        Ending = B
    Else
        Start = B
        Ending = A
    End If

    While Start <= Ending
        lblbetween1.Text = lblbetween1.Text & Start & " , "
        Start  = 1
    End While
End Sub

CodePudding user response：

With a For loop, you can choose the increment, so you can check which order the numbers are in and set the increment appropriately, for example:

Option Strict On
Imports System.Text

' ....

Private Sub btnAccept_Click(sender As Object, e As EventArgs) Handles btnAccept.Click
    Dim a = Integer.Parse(txtStart.Text)
    Dim b = Integer.Parse(txtEnd.Text)

    Dim inc As Integer = -1

    If a < b Then
        inc = 1
    End If

    Dim sb As New StringBuilder()

    For i = a To b Step inc
        sb.Append(i & " , ")
    Next

    lblbetween1.Text = sb.ToString()

End Sub

Fortunately, this still works if the numbers are equal, so there is no need for a special case for that.

It's better to use a StringBuilder to concatenate lots of strings, instead of just using & on lots of strings or the content of a control.

Option Strict On makes sure that the program doesn't try to do things with possibly unexpected results such as adding a number to a string. You should set it as the default for new projects.

CodePudding user response：

You could do something like this:

Will need to add

Imports System.Linq

and then

Dim a = 10I
Dim b = 15I

Dim start = Math.Min(a, b)
Dim count = Math.Max(a, b) - start

Dim series = Enumerable.Range(start, count   1).ToList

If b < a Then
  series.Reverse()
End If

Dim result = String.Join(",", series)