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run code in 200+ php & hhvm versions
Bugs & Features
<?php $a = 'hello, [how]. please don\'t remove [are] you?'; echo preg_replace('#\s*\[.+\]\s*#b', ' ', $a);
Output for 5.2.3 - 7.1.7
Warning: preg_replace(): Unknown modifier 'b' in /in/4GtEd on line 4
Output for 4.4.3 - 5.2.2
<br /> <b>Warning</b>: preg_replace() [<a href='function.preg-replace'>function.preg-replace</a>]: Unknown modifier 'b' in <b>/in/4GtEd</b> on line <b>4</b><br />
Output for 4.3.11 - 4.4.2
<br /> <b>Warning</b>: preg_replace(): Unknown modifier 'b' in <b>/in/4GtEd</b> on line <b>4</b><br />
Output for 4.3.0 - 4.3.10
<br /> <b>Warning</b>: Unknown modifier 'b' in <b>/in/4GtEd</b> on line <b>4</b><br />