Calling increment with array(1).
Setting $x=1 and calling increment with array($x).
PHP Warning:  Parameter 1 to increment() expected to be a reference, value given in /tmp/php-test-program.txt on line 14

Warning: Parameter 1 to increment() expected to be a reference, value given in /tmp/php-test-program.txt on line 14
After increment, $x is 1
Setting $array = array($x) and calling increment with $array.
PHP Warning:  Parameter 1 to increment() expected to be a reference, value given in /tmp/php-test-program.txt on line 19

Warning: Parameter 1 to increment() expected to be a reference, value given in /tmp/php-test-program.txt on line 19
After increment, x is 1
Calling decrement with array(1).
Setting $x=1 and calling decrement with array($x).
After decrement, $x is 1
Setting $array = array($x) and calling decrement with $array.
After decrement, x is 1