PowerShell SharePoint Module Iterating over all lists of a site collection
Example
Print out all list names and the item count.
$site = Get-SPSite -Identity https://mysharepointsite/sites/test
foreach ($web in $site.AllWebs)
{
foreach ($list in $web.Lists)
{
# Prints list title and item count
Write-Output "$($list.Title), Items: $($list.ItemCount)"
}
}
$site.Dispose()
