Powershell: combine contents of strings with dots inbetween, ignore empty ones - powershell

Question

Our naming convention consists of the first name, insertion, and lastname, all separated by dots. An example:
Stack Overflow = Stack.Overflow
Stack over Flow = Stack.over.flow
These outputs will be used later on in the script for the creation of a mailbox, user account, etc.
I've successfully combined the values of all strings by simply plus-ing them together, like this:
$Convention = $Firstname+"."+$Insertion+"."+$LastName
The values for these strings come from information being put in when the stript runs (Read-Host "....")
Now, I'm struggling with making this more dynamic. Of course, not every person has an insertion in their name. Using the given example, the current output of $Convention would be "Stack..Overflow", instead of "Stack.Overflow".
My question to you is: how can I filter out both, the $Insertion and the extra dot, when $Insertion is empty? It's most likely something very simple, but I can't seem to figure out what it is.
Thanks in advance for any given help!
Kr,
Robbert

Answer 1

I would do
$Convention = ('{0}.{1}.{2}' -f $Firstname, $Insertion, $LastName) -replace '\.+', '.'
The -replace uses regex in the first parameter, so '\.+', '.' means to replace 1 or more consecutive dots by a single dot.
Alternatively you could use regex \.{2,} which reads two or more consecutive dots
Example:
$Firstname = 'Robbert'
$Insertion = ''
$LastName = 'Verwaart'
$Convention = ('{0}.{1}.{2}' -f $Firstname, $Insertion, $LastName) -replace '\.+', '.'
Output:
Robbert.Verwaart

Answer 2

The code below will go through each of your $convention array, if this is an array, and test if the insertion is empty. If the $Insertion variable is empty, the $i will remove the $Insertion variable and the extra .. You need to add this into the script as a test, before creating the mailboxes.
foreach ($i in $convention){
if($insertion -eq "" -or $insertion -eq $null) {
$i= $Firstname+"."+$LastName
} else {
continue
}
}