オブジェクトの存在しないプロパティを参照したときの挙動

もしかしてオブジェクトの場合もか？ということで試したメモ。

Main.php

<?php

ini_set('error_reporting', E_ALL);
ini_set('display_errors', 1);

class A {
    public $a = null;
}
$a = new A();
var_dump($a->a);
var_dump($a->b);

実行結果。

$ for php in php56 php70 php71 php72 php73 php74 php80 php81 php82 ; do echo "===${php}===" ; ${php} Main.php ; done
===php56===
NULL
PHP Notice:  Undefined property: A::$b in /home/hhelibex/blog/2022-0614-01/Main.php on line 11

Notice: Undefined property: A::$b in /home/hhelibex/blog/2022-0614-01/Main.php on line 11
NULL
===php70===
NULL
PHP Notice:  Undefined property: A::$b in /home/hhelibex/blog/2022-0614-01/Main.php on line 11

Notice: Undefined property: A::$b in /home/hhelibex/blog/2022-0614-01/Main.php on line 11
NULL
===php71===
NULL
PHP Notice:  Undefined property: A::$b in /home/hhelibex/blog/2022-0614-01/Main.php on line 11

Notice: Undefined property: A::$b in /home/hhelibex/blog/2022-0614-01/Main.php on line 11
NULL
===php72===
NULL
PHP Notice:  Undefined property: A::$b in /home/hhelibex/blog/2022-0614-01/Main.php on line 11

Notice: Undefined property: A::$b in /home/hhelibex/blog/2022-0614-01/Main.php on line 11
NULL
===php73===
NULL
PHP Notice:  Undefined property: A::$b in /home/hhelibex/blog/2022-0614-01/Main.php on line 11

Notice: Undefined property: A::$b in /home/hhelibex/blog/2022-0614-01/Main.php on line 11
NULL
===php74===
NULL
PHP Notice:  Undefined property: A::$b in /home/hhelibex/blog/2022-0614-01/Main.php on line 11

Notice: Undefined property: A::$b in /home/hhelibex/blog/2022-0614-01/Main.php on line 11
NULL
===php80===
NULL
PHP Warning:  Undefined property: A::$b in /home/hhelibex/blog/2022-0614-01/Main.php on line 11

Warning: Undefined property: A::$b in /home/hhelibex/blog/2022-0614-01/Main.php on line 11
NULL
===php81===
NULL
PHP Warning:  Undefined property: A::$b in /home/hhelibex/blog/2022-0614-01/Main.php on line 11

Warning: Undefined property: A::$b in /home/hhelibex/blog/2022-0614-01/Main.php on line 11
NULL
===php82===
NULL
PHP Warning:  Undefined property: A::$b in /home/hhelibex/blog/2022-0614-01/Main.php on line 11

Warning: Undefined property: A::$b in /home/hhelibex/blog/2022-0614-01/Main.php on line 11
NULL
$ 

配列の場合と同様に、PHP 8.0から「Warning」に変わっている。

参考

hhelibex.hatenablog.jp hhelibex.hatenablog.jp