动态创建php 类函数或函数

1. 基础

变量函数：  

<?php  
$func = &#39;test&#39;;  
  
function test(){  
    echo &#39;yes !&#39;;  
}  
  
$func();  
?>

随机函数：

<?php  
$newfunc = create_function(&#39;$a,$b&#39;, &#39;return $a.$b;&#39;);  
echo "New anonymous function: $newfunc<br>";  
echo $newfunc(&#39;just&#39;, &#39;coding&#39;);  
?>

create_function — Create an anonymous (lambda-style) function

创建一个匿名函数。这个函数主要作用在unsort和array_walk的回调函数

$a,$b为参数，'return $a,$b' 为函数的代码

回调函数 :

<?php     
//5.3 以前     
$array = array( &#39;asbc&#39;, &#39;ddd&#39;, &#39;tttt&#39;, &#39;qqq&#39;);     
array_walk($array,create_function(&#39;&$item&#39;,&#39;$item=strtoupper($item);&#39;) ); //function(&$itm){$itm = strtoupper($itm);}     
print_r($array);  
  
//5.3 以后     
$array = array( &#39;asbc&#39;, &#39;ddd&#39;, &#39;tttt&#39;, &#39;qqq&#39;);     
array_walk($array,function(&$itm){$itm = strtoupper($itm);});      
print_r($array);  
?>

array_walk(array,function,userdata...)

array_walk() 函数对数组中的每个元素应用回调函数。如果成功则返回 TRUE，否则返回 FALSE。

典型情况下 function 接受两个参数。array 参数的值作为第一个，键名作为第二个。如果提供了可选参数 userdata ，将被作为第三个参数传递给回调函数。 

2. 实例动态创建类函数

<?php  
/* create class */  
class Record {  
    
    /* record information will be held in here */  
    private $info;  
    
    /* constructor */  
    function Record($record_array) {  
        $record_array[&#39;body&#39;] = &#39;this is a new attribution&#39;;  
        $this->info = $record_array;  
    }  
    
    /* dynamic function server */  
    function __call($method,$arguments) {  
        $meth = $this->from_case(substr($method,3,strlen($method)-3));  
        return array_key_exists($meth,$this->info) ? $this->info[$meth] : false;  
    }  
    
    function from_case($str) {  
        $str[0] = strtolower($str[0]);  
        $func = create_function(&#39;$c&#39;, &#39;return "_" . strtolower($c[1]);&#39;); // function ($c) { return "_" . strtolower($c[1]); }  
        return preg_replace_callback(&#39;/([A-Z])/&#39;, $func, $str);  
    }    
}  
  
  
/* usage */  
$Record = new Record(  
    array(  
        &#39;id&#39; => 12,  
        &#39;title&#39; => &#39;Greatest Hits&#39;,  
        &#39;description&#39; => &#39;The greatest hits from the best band in the world!&#39;  
    )  
);  
  
/* proof it works! */  
echo &#39;The ID is:  &#39;.$Record->getId().&#39;<br>&#39;; // returns 12    
echo &#39;The Title is:  &#39;.$Record->getTitle().&#39;<br>&#39;; // returns "Greatest Hits"  
echo &#39;The Description is:  &#39;.$Record->getDescription().&#39;<br>&#39;; //returns "The greatest hits from the best band in the world!"  
echo &#39;The Body is:  &#39;.$Record->getBody(); //returns "The greatest hits from the best band in the world!"  
?>

重点在于： __call 和 create_function