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php中instanceof 与 is_a()区别分析_php技巧

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May 16, 2016 pm 08:22 PM

instanceofphp

instanceof 运算符和 is_a() 方法都是判断：某对象是否属于该类或该类是此对象的父类（用于确定一个 PHP 变量是否属于某一类 class 的实例）

是的话返回 TRUE，不是的话返回 FALSE

区别：

instanceof 运算符是 PHP 5 引进的。在此之前用 is_a()，但是后来 is_a() 被废弃而用 instanceof 替代了。

注意：

PHP 5.3.0 起，又恢复使用 is_a() 了。

总结：

现在PHP的服务环境普遍都使用PHP5.0+了，所以尽量使用 instanceof 来代替 is_a()

综上，如果你不知道你的服务器环境，那么建议你使用instanceof，以免造成不必要的麻烦

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