粗略的了解一下php中的迭代器,感觉只会用foreach的人是不是应该弱弱的鄙视一下自己,嘻嘻
<span style="font-size:14px;"><?php
iterator部分
能够使用数组的迭代器实现限制数组个数,过滤数组的元素
*/
$array_test=array(
"a" => "naME",
"B" => "VALUE",
"C" => "2"
);
$iterator = new ArrayIterator($array_test);
//实现一个限制个数的规则,直接使用的静态类
$limitIterator = new LimitIterator($iterator,0,2);
foreach($limitIterator as $key =>$value){
echo "<pre>".$key.":".$value."</pre>".PHP_EOL;
}
//输出结果
/*
a:naME
B:VALUE
*/
class eventFilterIterator extends FilterIterator{
//实现一个过滤的规则,包装成一个类对象,来使用,是一个数据结构。
public function accept(){
$iterator=$this->getInnerIterator();
$key=$iterator->key();
if($key==='a'){
return true;
}
return false;
}
}
$filterIterator = new eventFilterIterator($iterator);
foreach($filterIterator as $key =>$value){
echo "<pre>".$key.":".$value."</pre>".PHP_EOL;
}
/*
返回结果
a:naME
*/
//诸如RecursiveIteratorIterator/RegexIterator
$directoryIterator=new RecursiveDirectoryIterator('./');
$recursiveIterator=new RecursiveIteratorIterator($directoryIterator);
//对迭代器的再次封装
$regexFilter=new RegexIterator($recursiveIterator,'/(.*?)\.(php)$/');
foreach($regexFilter as $key =>$value){
echo "<pre>".$key.":".$value."</pre>".PHP_EOL;
}
/*
.\controller\db\systemDB\driver.php:.\controller\db\systemDB\driver.php
.\controller\lotteryrd.php:.\controller\lotteryrd.php
.\controller\uploadcontroller.php:.\controller\uploadcontroller.php
.\include\json.php:.\include\json.php
.\include\uploadfile.php:.\include\uploadfile.php
.\models\uploadfilein.php:.\models\uploadfilein.php
.\route.php:.\route.php
.\test.php:.\test.php
.\upload.php:.\upload.php
.\web\dojson.php:.\web\dojson.php
.\web\doxml.php:.\web\doxml.php
.\web\index.php:.\web\index.php
*/
?>
</span>