PHP ʖ²ἯTH º󍋼/A Ղ 15. ҽӃµĽ⊍ ȡϻҽӃ $a = 1; $b = $a; unset ($a); º󍋼/A ưµ㼯A ҽӃ·µ»ؼ/TD ɏһ¼¶ ҽӃ¶¨λ