Online PHP editor | output for C9Zsn

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: Notice: Only variables should be passed by reference in /in/C9Zsn on line 4 string(6) "fooooo" Fatal error: Uncaught TypeError: Cannot access offset of type string on string in /in/C9Zsn:8 Stack trace: #0 {main} thrown in /in/C9Zsn on line 8
Process exited with code 255.
Output for 7.0.0 - 7.0.20, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.31, 7.4.0 - 7.4.33: Notice: Only variables should be passed by reference in /in/C9Zsn on line 4 string(6) "fooooo" Warning: Illegal string offset 'foo' in /in/C9Zsn on line 8 Fatal error: Uncaught Error: Cannot use string offset as an array in /in/C9Zsn:8 Stack trace: #0 {main} thrown in /in/C9Zsn on line 8
Process exited with code 255.
Output for 7.3.32 - 7.3.33: string(6) "fooooo" Warning: Illegal string offset 'foo' in /in/C9Zsn on line 8 Fatal error: Uncaught Error: Cannot use string offset as an array in /in/C9Zsn:8 Stack trace: #0 {main} thrown in /in/C9Zsn on line 8
Process exited with code 255.
Output for 5.4.0 - 5.4.45, 5.5.24 - 5.5.35, 5.6.8 - 5.6.28: Strict Standards: Only variables should be passed by reference in /in/C9Zsn on line 4 string(6) "fooooo" Warning: Illegal string offset 'foo' in /in/C9Zsn on line 8 Fatal error: Cannot use string offset as an array in /in/C9Zsn on line 8
Process exited with code 255.
Output for 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29: Strict Standards: Only variables should be passed by reference in /in/C9Zsn on line 4 string(6) "fooooo" Fatal error: Cannot use string offset as an array in /in/C9Zsn on line 8
Process exited with code 255.
Output for 5.0.5: Fatal error: Only variables can be passed by reference in /in/C9Zsn on line 4
Process exited with code 255.
Output for 5.0.0 - 5.0.4: string(6) "fooooo" Fatal error: Cannot use string offset as an array in /in/C9Zsn on line 8
Process exited with code 255.
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9: string(6) "fooooo" string(6) "fooooo"