Supported Versions: PHP 4, PHP 5, PHP 7, PHP 8
Prints human-readable information about a variable
print_r(mixed $valuebool $return false): string|bool
            sprintf(

                
'Event [%s] does not have the [%s] listener attached to it',

                
$expectedEvent,

                
print_r($expectedListenertrue)

            )

        );

    }