Online PHP editor | output for ZSfaN

Output for 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.7: Warning: Undefined variable $json in /in/ZSfaN on line 3 null
Output for 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.20, 7.2.6 - 7.2.33, 7.3.12 - 7.3.31, 7.4.0 - 7.4.25, 7.4.27 - 7.4.33: Notice: Undefined variable: json in /in/ZSfaN on line 3 null
Output for 7.3.32 - 7.3.33, 7.4.26: null
Output for 5.3.0 - 5.3.29: Notice: Undefined variable: json in /in/ZSfaN on line 3 Notice: Use of undefined constant JSON_PRETTY_PRINT - assumed 'JSON_PRETTY_PRINT' in /in/ZSfaN on line 3 Warning: json_encode() expects parameter 2 to be long, string given in /in/ZSfaN on line 3
Output for 5.2.0 - 5.2.17: Notice: Undefined variable: json in /in/ZSfaN on line 3 Notice: Use of undefined constant JSON_PRETTY_PRINT - assumed 'JSON_PRETTY_PRINT' in /in/ZSfaN on line 3 Warning: json_encode() expects exactly 1 parameter, 2 given in /in/ZSfaN on line 3
Output for 5.0.0 - 5.0.5, 5.1.0 - 5.1.6: Fatal error: Call to undefined function json_encode() in /in/ZSfaN on line 3
Process exited with code 255.
Output for 4.4.5 - 4.4.9: Fatal error: Call to undefined function: json_encode() in /in/ZSfaN on line 3
Process exited with code 255.
Output for 4.3.2 - 4.3.11, 4.4.0 - 4.4.4: Fatal error: Call to undefined function: json_encode() in /in/ZSfaN on line 3
Process exited with code 255.
Output for 4.3.0 - 4.3.1: Fatal error: Call to undefined function: json_encode() in /in/ZSfaN on line 3