Working With Arrays

I am looking to create a function to gather inputs for an array. I can only find the param value that would go within another function, however I would like to have something that users could do once, and the values would be placed into the Array names, $ComputerName and $UserName.

Here is what I have at the beginning of each other function;

function Fill-Variables { [CmdletBinding()] param ( [Parameter(Mandatory=$true, ValueFromPipeline=$true, ValueFromPipelineByPropertyName=$true, Position=0)] [Alias("hostname")] [String[]]$ComputerName, [Parameter(Mandatory=$true, ValueFromPipeline=$false, Position=1)] [String]$UserName ) }