3v4l.org

run code in 300+ PHP versions simultaneously
<?php $x = [ '"\"', '001', 'nulll', '""' ]; foreach ($x as $y) { var_dump([json_decode($y), json_last_error()]); }
Output for 7.0.0 - 7.0.20, 7.1.0 - 7.1.20, 7.2.6 - 7.2.33, 7.3.16 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
array(2) { [0]=> NULL [1]=> int(3) } array(2) { [0]=> NULL [1]=> int(4) } array(2) { [0]=> NULL [1]=> int(4) } array(2) { [0]=> string(0) "" [1]=> int(0) }
Output for 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.28
array(2) { [0]=> NULL [1]=> int(4) } array(2) { [0]=> int(1) [1]=> int(0) } array(2) { [0]=> NULL [1]=> int(4) } array(2) { [0]=> string(0) "" [1]=> int(0) }

preferences:
196.83 ms | 402 KiB | 269 Q