Online PHP editor | output for W24t2

Output for 8.3.0 - 8.3.7: Warning: Undefined variable $aMonthLabels in /in/W24t2 on line 4 Warning: Trying to access array offset on null in /in/W24t2 on line 4 Fatal error: Uncaught ArgumentCountError: substr() expects at least 2 arguments, 1 given in /in/W24t2:4 Stack trace: #0 /in/W24t2(4): substr('1993') #1 {main} thrown in /in/W24t2 on line 4
Process exited with code 255.
Output for 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18: Warning: Undefined variable $aMonthLabels in /in/W24t2 on line 4 Warning: Trying to access array offset on value of type null in /in/W24t2 on line 4 Fatal error: Uncaught ArgumentCountError: substr() expects at least 2 arguments, 1 given in /in/W24t2:4 Stack trace: #0 /in/W24t2(4): substr('1993') #1 {main} thrown in /in/W24t2 on line 4
Process exited with code 255.
Output for 7.4.0 - 7.4.25, 7.4.27 - 7.4.33: Notice: Undefined variable: aMonthLabels in /in/W24t2 on line 4 Notice: Trying to access array offset on value of type null in /in/W24t2 on line 4 Warning: substr() expects at least 2 parameters, 1 given in /in/W24t2 on line 4 23
Output for 7.3.32 - 7.3.33, 7.4.26: Warning: substr() expects at least 2 parameters, 1 given in /in/W24t2 on line 4 23
Output for 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.30, 7.0.0 - 7.0.20, 7.1.0 - 7.1.20, 7.2.0 - 7.2.33, 7.3.12 - 7.3.31: Notice: Undefined variable: aMonthLabels in /in/W24t2 on line 4 Warning: substr() expects at least 2 parameters, 1 given in /in/W24t2 on line 4 23
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: Parse error: syntax error, unexpected '[' in /in/W24t2 on line 2
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/W24t2 on line 2
Process exited with code 255.
Output for 4.3.2 - 4.3.4: Parse error: parse error in /in/W24t2 on line 2
Process exited with code 255.