Online PHP editor | output for klZl1

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: bool(true) bool(false) Fatal error: Uncaught TypeError: Unsupported operand types: string + string in /in/klZl1:9 Stack trace: #0 {main} thrown in /in/klZl1 on line 9
Process exited with code 255.
Output for 7.1.0 - 7.1.20, 7.2.6 - 7.2.33, 7.3.12 - 7.3.33, 7.4.0 - 7.4.33: bool(true) bool(false) Warning: A non-numeric value encountered in /in/klZl1 on line 9 Warning: A non-numeric value encountered in /in/klZl1 on line 9 bool(true) bool(false)
Output for 5.4.4 - 5.4.45, 5.5.24 - 5.5.35, 5.6.8 - 5.6.28, 7.0.0 - 7.0.20: bool(true) bool(false) bool(true) bool(false)
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.3: bool(true) bool(true) bool(true) bool(false)