Online PHP editor | output for 9DlUe

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: Fatal error: Uncaught TypeError: array_merge(): Argument #4 must be of type array, int given in /in/9DlUe:6 Stack trace: #0 /in/9DlUe(6): array_merge(Array, Array, Array, 34) #1 {main} thrown in /in/9DlUe on line 6
Process exited with code 255.
Output for 7.3.0 - 7.3.33, 7.4.0 - 7.4.33: Warning: array_merge(): Expected parameter 4 to be an array, int given in /in/9DlUe on line 6 array(1) { [0]=> NULL }
Output for 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 - 5.4.45, 5.5.24 - 5.5.35, 5.6.7 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.33, 7.2.5 - 7.2.33: Warning: array_merge(): Argument #4 is not an array in /in/9DlUe on line 6 array(1) { [0]=> NULL }
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9: array(1) { [0]=> array(10) { [0]=> array(3) { [0]=> int(1) [1]=> int(2) [2]=> int(3) } [1]=> array(1) { [0]=> int(2) } [2]=> int(3) [3]=> array(3) { [0]=> int(1) [1]=> int(2) [2]=> int(3) } [4]=> array(1) { [0]=> int(2) } [5]=> int(3) [6]=> array(3) { [0]=> int(2) [1]=> int(3) [2]=> int(4) } [7]=> array(1) { [0]=> int(3) } [8]=> int(4) [9]=> int(34) } }