PowerShell “Period” operator, what does it do?

Question

I\'ve been looking online for a specific answer to better help me understand how this works. In PHP we use the \" . \" to concatenate strings. However in powershell I see things

Answer 1

It's the member access operator. $_ is a special variable (the loop variable in this case). Therefore, $_.extension accesses or invokes the property extension on $_.