phpforeach参数强制类型转换的问题_PHP教程

class service implements Iterator{ 
function __construct($service_define,$filter=null){ 
$this->iterator = new ArrayIterator($service_define['list']); 
$this->filter = $filter; 
$this->valid(); 
} 
function current(){ 
return $this->current_object; 
} 
public function rewind() { 
$this->iterator->rewind(); 
} 
public function key() { 
return $this->iterator->current(); 
} 
public function next() { 
return $this->iterator->next(); 
} 
public function valid() { 
while($this->iterator->valid()){ 
if($this->filter()){ 
return true; 
}else{ 
$this->iterator->next(); 
} 
}; 
return false; 
} 
private function filter(){ 
$current = $this->iterator->current(); 
if($current){ 
$this->current_object = new Sameple($current); 
if($this->current_object){ 
return true; 
} 
} 
return false; 
} 
} 
class Sameple{ 
var $class_name; 
function __construct($class_name = null) { 
$this->class_name = $class_name; 
} 
function show(){ 
echo $this->class_name,'
'; 
} 
} 
$servicelist = array( 
'list' => array( 
'first', 
'second', 
'third', 
'fourth', 
), 
); 
$ser = new service($servicelist); 
foreach ($ser as $s) { 
$s->show(); 
} 
/* 
//执行报错的代码 使用了将$ser执行强制类型转换操作 
foreach ((array)$ser as $s) { 
$s->show(); 
}*/ 
 
之所以出现这样的问题就是，foreach不但可以遍历数组，还可以遍历实现了Iterator接口的类。 

我以前只注意到了数组的情况，把实现了Iterator接口的类的情况给忽略了。以后一定会注意。 
依次为记。

http://www.bkjia.com/PHPjc/322584.htmlwww.bkjia.comtruehttp://www.bkjia.com/PHPjc/322584.htmlTechArticle所以，为了防止这样的信息出现，我使用foreach的时候，都会把参数进行强制类型转换，形势如下： foreach((array)$arr as $key = $value); 这样做一直...