What is the equivalent of Set X = Nothing in PHP?

Question

Is:

<%
Set Mail = Server.CreateObject("SomeCOMObject")

Set Mail = Nothing
%>

the same as:

<?php
$Mail = new COM("SomeCOMObject");

$Mail->Close(); // <---- Not sure about this
?>

Answer 1

I beleive

$Mail = null;
unset($Mail);

Although I am likely mistaken.

Answer 2

$mail = new Mail; //hello
unset($mail); //goodbye

Answer 3

You can set $var to equal nothing like this:

$var = null;

To completely release the variable from memory, you do this:

unset($var);