<?php
$string = 'this is some code and it has bbcode in it like [image width="740" height="249" parameters=""]51lca7dn56.jpg[/image] for example and [image parameters="test" height="123" width="456"]12345.jpg[/image].' ;
if ( preg_match_all ( '/\[image\b(?=(?:[^\]]*\bwidth="(\d+)"|))(?=(?:[^\]]*\bheight="(\d+)"|))(?=(?:[^\]]*\bparameters="([^"]*)"|))[^\]]*\]([^\[]*)\[\/image\]/i' , $string , $match ) > 0 ) { }
?>
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