PHP ʖ²ἯTH º󍋼/A Ղ 7. Ѝ ±¾΄µµ֐ʹӃµĎ± Ѝ mixed number callback ¶ԓڃ»Ӑʵ=»¯Ϊ¶ԏ󵄾²̬ £¬Ҫ´«µ݆䷽·¨£¬½«ʽש 0 ς±ꖸ÷µĶԏ󃻻»³ɸÀൄû³Ƽ´¿ɡ£ =ד 7-11. Callback º¯ʽʵ= ?php // simple callback example function foobar() {echo "hello world!";} call_user_function("foobar"); // method callback examples class foo {function bar() {echo "hello world!";}} $foo = new foo; call_user_function(array($foo, "bar")); // object method call call_user_function(array("foo", "bar")); // static class method call? º󍋼/A ưµ㼯A NULL ɏһ¼¶ ЍϷ·¨