結果3
Fatal error: Uncaught TypeError: count(): Argument #1 ($value) must be of type Countable|array, null given in /home/kyoto-edu/www/weblesson/php/07.IO/result3ref.php:13
Stack trace:
#0 {main}
thrown in /home/kyoto-edu/www/weblesson/php/07.IO/result3ref.php on line 13