Online PHP editor | output for LK6b8

Output for 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.4, 8.3.6: Fatal error: Uncaught Error: Undefined constant "is_numeric" in /in/LK6b8:2 Stack trace: #0 {main} thrown in /in/LK6b8 on line 2
Process exited with code 255.
Output for 8.3.5: Warning: PHP Startup: Unable to load dynamic library 'sodium.so' (tried: /usr/lib/php/8.3.5/modules/sodium.so (libsodium.so.23: cannot open shared object file: No such file or directory), /usr/lib/php/8.3.5/modules/sodium.so.so (/usr/lib/php/8.3.5/modules/sodium.so.so: cannot open shared object file: No such file or directory)) in Unknown on line 0 Fatal error: Uncaught Error: Undefined constant "is_numeric" in /in/LK6b8:2 Stack trace: #0 {main} thrown in /in/LK6b8 on line 2
Process exited with code 255.
Output for 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33: Warning: Use of undefined constant is_numeric - assumed 'is_numeric' (this will throw an Error in a future version of PHP) in /in/LK6b8 on line 2 array(6) { [0]=> int(45) [1]=> string(2) "15" [3]=> int(1) [4]=> int(2) [5]=> string(1) "3" [6]=> int(4) }
Output for 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33: Notice: Use of undefined constant is_numeric - assumed 'is_numeric' in /in/LK6b8 on line 2 array(6) { [0]=> int(45) [1]=> string(2) "15" [3]=> int(1) [4]=> int(2) [5]=> string(1) "3" [6]=> int(4) }