Online PHP editor | output for lQQJQ

Output for 4.3.0 - 4.3.2: array(4) { [0]=> string(2) "ac" [1]=> string(1) "a" [2]=> string(0) "" [3]=> string(1) "c" } Notice: Use of undefined constant PREG_UNMATCHED_AS_NULL - assumed 'PREG_UNMATCHED_AS_NULL' in /in/lQQJQ on line 5 array(4) { [0]=> string(2) "ac" [1]=> string(1) "a" [2]=> string(0) "" [3]=> string(1) "c" }
Output for 4.3.3 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.40: array(4) { [0]=> string(2) "ac" [1]=> string(1) "a" [2]=> string(0) "" [3]=> string(1) "c" } Notice: Use of undefined constant PREG_UNMATCHED_AS_NULL - assumed 'PREG_UNMATCHED_AS_NULL' in /in/lQQJQ on line 5 Warning: preg_match() expects parameter 4 to be long, string given in /in/lQQJQ on line 5 array(4) { [0]=> string(2) "ac" [1]=> string(1) "a" [2]=> string(0) "" [3]=> string(1) "c" }
Output for 7.0.0 - 7.0.33, 7.1.0 - 7.1.33: array(4) { [0]=> string(2) "ac" [1]=> string(1) "a" [2]=> string(0) "" [3]=> string(1) "c" } Notice: Use of undefined constant PREG_UNMATCHED_AS_NULL - assumed 'PREG_UNMATCHED_AS_NULL' in /in/lQQJQ on line 5 Warning: preg_match() expects parameter 4 to be integer, string given in /in/lQQJQ on line 5 array(4) { [0]=> string(2) "ac" [1]=> string(1) "a" [2]=> string(0) "" [3]=> string(1) "c" }
Output for 7.2.0 - 7.2.34, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.34, 8.2.0 - 8.2.34, 8.3.0 - 8.3.35, 8.4.1 - 8.4.26, 8.5.0 - 8.5.11: array(4) { [0]=> string(2) "ac" [1]=> string(1) "a" [2]=> string(0) "" [3]=> string(1) "c" } array(4) { [0]=> string(2) "ac" [1]=> string(1) "a" [2]=> NULL [3]=> string(1) "c" }