PHP中return的用法

dly · 发表于 2012-2-16 13:42:58

这两天，Charles研究Yii框架的使用，注意到Yii的配置文件，采用一种写法。如下：

/**
* 注释若干
* 以下是一个格式如config.php的文件
*/
return array(
'config1' => 'some value',
'config2' => 'some value',
);
?>

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在这个文件中，直接就写了一个return，这个用法又一次突破了我的常识。特意查询了一下文档，里面这样描述的：

return
If called from within a function, the return() statement immediately ends execution of the current function, and returns its argument as the value of the function call. return() will also end the execution of an eval() statement or script file.
If called from the global scope, then execution of the current script file is ended. If the current script file was include()ed or require()ed, then control is passed back to the calling file. Furthermore, if the current script file was include()ed, then the value given to return() will be returned as the value of the include() call. If return() is called from within the main script file, then script execution ends. If the current script file was named by the auto_prepend_file or auto_append_file configuration options in php.ini, then that script file's execution is ended.

return语句可以终止函数执行那自不必说了，这里还提到了可以终止eval过程的进行，并且如果处于被include的文件中，还能使return的值成为include和require函数的返回值。这样写的好处是，一个语句就可以得到配置项的内容了。

//原来这样写
require './config.php';
function test() {
global $config;
if ($config['a']=='b') echo 'hello';
}
//现在
function test() {
$config = require('./config.php');
if ($config['a']=='b') echo 'hello';
}
?>

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PHP中return的用法

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