Online PHP editor | output for ucSbZ

Output for 7.3.17 - 7.3.33, 7.4.5 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.32, 8.2.0 - 8.2.28, 8.3.0 - 8.3.19, 8.4.1 - 8.4.5: string(4) "bar1" string(4) "bar2" NULL
Output for 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.16, 7.4.0 - 7.4.4: string(4) "bar1" string(4) "bar2" Fatal error: Uncaught RuntimeException: Index invalid or out of range in /in/ucSbZ:9 Stack trace: #0 {main} thrown in /in/ucSbZ on line 9
Process exited with code 255.
Output for 4.4.2 - 4.4.9, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.40: Parse error: syntax error, unexpected '?' in /in/ucSbZ on line 7
Process exited with code 255.
Output for 4.3.0 - 4.3.1, 4.3.5 - 4.3.11, 4.4.0 - 4.4.1, 5.0.0 - 5.0.5: Parse error: parse error, unexpected '?' in /in/ucSbZ on line 7
Process exited with code 255.
Output for 4.3.2 - 4.3.4: Parse error: parse error in /in/ucSbZ on line 7
Process exited with code 255.