<?php
 
$re = '@\[([a-zA-Z0-9]+)\]|[][=?~#!]@';
$strs =array('DeviceLocation[West12]', '#=Device', '?[1234]=#Martin');
 
foreach ($strs as $str) {
	preg_match_all($re, $str, $matches, PREG_SET_ORDER);
	$results = array();
	$match_val = "";
	foreach ($matches as $m) {
		if (!empty($m[1])) {
			$match_val = trim($m[1], "[]");
			array_push($results, "[]");
		} else {
			array_push($results, $m[0]);
		} 
	}
	echo "Value: " . $match_val . "\n";
	echo "Symbols: " . implode(", ", $results);
	echo "\n-----\n";
}
 

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