Get list of all user-defined vars

local_vars_dump.php

<?php
       // list of keys to ignore (including the name of this variable)
        $ignore = array('GLOBALS', '_FILES', '_COOKIE',  '_POST', '_GET', '_SERVER', '_ENV', 'ignore');
        // diff the ignore list as keys after merging any missing ones with the defined list
        $vars = array_diff_key(get_defined_vars() + array_flip($ignore), array_flip($ignore));
        // should be left with the user defined var(s) (in this case $testVar)
        var_dump($vars);