PowerShell Basics: Detecting if a String Ends with a Certain Character

I don't think this situation really calls for regex.

PowerShell is capable of indexing a string just like a character array, and its comparison system can convert data types when needed. As a result, you can do something very straightforward like this:

$String = "When Lords and Ladies quest for fame, a Beast will touch the land with flame."

if ( $String[-1] -eq '.' ) {
    # Do something
}
else {
    # Do something else
}

Also, if this is about checking if a path is a container or leaf object, you can do that much more effectively, thoroughly, and verbosely like this:

Test-Path -Path "C:\MyFolder" -PathType Container

And if the path might not exist you can add -IsValid to that call, although in that case I believe the -PathType isn't particularly useful there and then, perhaps, some more manual checking might be a bit more useful depending on your specific use case.