3v4l.org

run code in 300+ PHP versions simultaneously
<?php echo 'test1: '; echo '<h1>' + 'hello' + '</h1>'; echo "\n" . 'test2'; echo '<h1>100' + 'hello' + '</h1>'; echo "\n" . 'test3'; echo '<h1>100' . 'hello' . '</h1>'; echo "\n" . 'test4'; echo '<h1>' . 'hello' . '</h1>';
Output for 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
test1: Fatal error: Uncaught TypeError: Unsupported operand types: string + string in /in/0osm0:4 Stack trace: #0 {main} thrown in /in/0osm0 on line 4
Process exited with code 255.
Output for 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33
test1: Warning: A non-numeric value encountered in /in/0osm0 on line 4 Warning: A non-numeric value encountered in /in/0osm0 on line 4 Warning: A non-numeric value encountered in /in/0osm0 on line 4 0 test2 Warning: A non-numeric value encountered in /in/0osm0 on line 6 Warning: A non-numeric value encountered in /in/0osm0 on line 6 Warning: A non-numeric value encountered in /in/0osm0 on line 6 0 test3<h1>100hello</h1> test4<h1>hello</h1>
Output for 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.40, 7.0.0 - 7.0.33
test1: 0 test20 test3<h1>100hello</h1> test4<h1>hello</h1>
preferences:
250.9 ms | 402 KiB | 376 Q