Android Question delete some items from list

[Addo]

i have the followig list and i want to delete the whole list and leave the last 4 items was inserted in the list based on some condition , is it possible ?

dim Type cmdline(command as string)
dim CommandList As List

if CommandList.Size  > 50 then

For i = 0 To CommandList.Size - 1
Dim cmd As cmdline
cmd = CommandList.Get(i)
'here i want to delete all items that contain something and leave the last 4 items inserted how can i possibly do that ?
If cmd.command = "something" Then
CommandList.RemoveAt(i)
End If


Next

End if

 

[OliverA]

Not a solution, just a tip. You need to start from the top of the list and work down when you are removing items from the list, otherwise you will not get the results you want.

 

[Addo]

i have started the loop from top but i am not sure on how to skip the last 4 items in the list while removing

if CommandList.Size  > 50 then

For i =  CommandList.Size -1 To 0 Step -1
Dim cmd As cmdline
cmd = CommandList.Get(i)
If cmd.command = "something" Then
CommandList.RemoveAt(i)
End If


Next

End if

 

[mangojack]

i have started the loop from top but i am not sure on how to skip the last 4 items in the list while removing

Are you referring to the last 4 items that were added to the list ? .. then

For i =  CommandList.Size -5 To 0 Step -1

 

[DonManfred]

PUT ON your brain! It is simple MATH.

For i = CommandList.Size -1 To 0 Step -1

CommandList.Size -1 is the last item.
CommandList.Size -1-4 is 4 items less then the last.

For i =  CommandList.Size -5 To 0 Step -1

 

[Addo]

i was asking about the last 4 items that equal to same condition "something" because this list will have multiable items with a different commands name skipping the last 4 items in the total list will remove the last 4 items if they equal the condition "something" but what if the last 4 items are mixed with different names

i think i should calculate each loop with a global integer and count each "something" condition in order to target those conditions only i know that i should set size- if i want to skip this order in list i got misunderstood

 

[DonManfred]

Untested but i think it should bring your the in the right direction!?

    If CommandList.Size  > 50 Then
        Dim toRemove As List
        toRemove.Initialize
        For i =  CommandList.Size -1 To 0 Step -1
            Dim cmd As cmdline
            cmd = CommandList.Get(i)
            If cmd.command = "something" Then
                'CommandList.RemoveAt(i)
                toRemove.Add(i)
            End If
        Next
        '
        If toRemove.Size>4 Then
            For i = toRemove.Size -5 To 0 Step -1
                CommandList.RemoveAt(toRemove.Get(i))
            Next
        End If
    End If

 

[emexes]

'here i want to delete all items that contain something and leave the last 4 items inserted how can i possibly do that ?
Do While CommandList.Size > 4
    CommandList.RemoveAt(0)
Loop

 

[OliverA]

If your list items are
1,9,2,9,3,9,4,9,5,9,9,9,9
And the item 9 is what you are looking for, then should the end result be
1,2,3,4,5,9,9,9,9
Or
1,9,2,9,3,9,4,9,5
Or
9,9,9,9 and it is all the 9’s before the 5
Or
9,9,9,9 and it is all the 9’s after the 5