Home > php教程 > php手册 > body text

php判断类是否存在函数 class_exists

WBOY
Release: 2016-06-13 11:17:38
Original
1357 people have browsed it

php判断类是否存在函数 class_exists//bool class_exists ( string $class_name [, bool $autoload = true ] )//此功能是否给定的类被定义检查。This function checks whether or not the given class has been defined.  

php教程判断类是否存在函数 class_exists
//bool class_exists ( string $class_name [, bool $autoload = true ] )
//此功能是否给定的类被定义检查。this function checks whether or not the given class has been defined.

//返回true,如果class_name是一个定义的类,否则返回false。
//实例

if (class_exists('myclass')) {
    $myclass = new myclass();
}

 

function __autoload($class)
{
    include($class . '.php');

    // check to see whether the include declared the class
    if (!class_exists($class, false)) {
        trigger_error("unable to load class: $class", e_user_warning);
    }
}

if (class_exists('myclass')) {
    $myclass = new myclass();
}


Related labels:
source:php.cn
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Popular Recommendations
Popular Tutorials
More>
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template
About us Disclaimer Sitemap
php.cn:Public welfare online PHP training,Help PHP learners grow quickly!