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run code in 150+ php & hhvm versions
Bugs & Features
<?php $str = "&lt;p>This is a good text, but it's very tedious. &lt;/p>"; $str = preg_replace("/(?<!\.\s*?)&lt;\/p>/", "$1.&lt;\/p>", $str); echo $str;
Output for 4.3.11 - 5.6.28, 7.0.0 - 7.1.0
Warning: preg_replace(): Compilation failed: lookbehind assertion is not fixed length at offset 10 in /in/Rf8O2 on line 4
Output for 4.3.0 - 4.3.10, hhvm-3.10.0 - 3.12.0
Warning: Compilation failed: lookbehind assertion is not fixed length at offset 10 in /in/Rf8O2 on line 4