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HomeBackend DevelopmentPHP Tutorial理解PHP中的stdClass类_php技巧

相信大家跟我一样,会经常看到和下面很类似的PHP代码:

复制代码 代码如下:

$user = new stdClass();
$user->name = 'gouki';

这样的代码,这是干嘛用的呢?
翻开手册,搜索stdClass,你会发现,手册上几乎没有介绍,如果你再次搜索google,看到的也几乎全是英文解释。
其实,stdClass在PHP5才开始被流行。而stdClass也是zend的一个保留类。似乎没有其他作用。也几乎没有任何说明。
或者,我们可以这么理解:stdClass是PHP的一个基类,所有的类几乎都继承这个类,所以任何时候都可以被new,可以让这个变量成为一个object。同时,这个基类又有一个特殊的地方,就是没有方法。
凡时用new stdClass()的变量,都不可能会出现$a->test()这种方式的使用。
或者,我们可以又这么理解一下,正因为PHP5的对象的独特性,对象在任何地方被调用,都是引用地址型的,所以相对消耗的资源会少一点。在其它页面为它赋值时是直接修改,而不是引用一个拷贝。
例如:

复制代码 代码如下:

$user = new stdClass();
$user->name = 'gouki';
$myUser = $user;
$myUser->name = 'flypig';

如果在PHP4时代,这样的代码就是在消耗系统资源。因为:
$myUser = $user;
这是创建了一个拷贝。所以,在PHP4的时候,都是这样使用:
复制代码 代码如下:

$myUser = & $user;

有人说,为什么不用数组呢?数组不是更方便吗?而且对于PHP这样的弱类型程序来说,用数组应该是最方便的。
确实。数组在程序的使用中应该是最方便的,然而数组的每次被引用($a = $b),其实都是创建了一个副本,而且,数组被unset后,还是占用了内存(这个是听人说来的,我没有测试……也不知道怎么测试,如果有人知道,请告诉我,谢谢 )
不过SPL的标准类库里,还有一个函数arrayobject,可以直接将数组转化为对象这也是一个好办法哦。
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