3v4l.org

run code in 300+ PHP versions simultaneously
<?php $str = ' #chapter 1: title 1 content chapter 1 line 1 content chapter 1 line 2 content chapter 1 line 3 content chapter 1 line 4 #chapter 2: title 2 content chapter 2 line 1 '; preg_match_all('/#Chapter\h+\d+:\h+title\h+\d+\K(?:\R(?!#chapter).*)*/i',$str, $match); print_r($match[0]);
Output for 7.1.25 - 7.1.30, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.33, 8.2.0 - 8.2.29, 8.3.0 - 8.3.25, 8.4.1 - 8.4.12
Array ( [0] => content chapter 1 line 1 content chapter 1 line 2 content chapter 1 line 3 content chapter 1 line 4 [1] => content chapter 2 line 1 )
preferences:
145.19 ms | 408 KiB | 5 Q