How do I parse a string for a particular delimited section within PHP?

I have a string, for example "[{XYZ123}] This is a test" and need to parse out the content in between the [{ and }] and dump into another string. I assume a regular expression is in order to accomplish this but as it's not for the faint of heart, I did not attempt and need your assi开发者_StackOverflow社区stance.

What is the best way to pull the fragment in between the [{ and }]? Thanks in advance for your help!

<?php
$str = "[{XYZ123}] This is a test";

if(preg_match('/\[{(.*?)}\]/',$str,$matches)) {

 $dump = $matches[1];

 print "$dump";  // prints XYZ123
}

?>

$str = "[{XYZ123}] This is a test";
$s = explode("}]",$str);
foreach ($s as $k){
  if ( strpos($k,"[{") !==FALSE ){
    $t = explode("[{",$k); #or use a combi of strpos and substr()
    print $t[1];
  }
}

The regex would be (?=\[\{).*(?=\}\]), though I don't know if php supports look aheads.