PHP SPL 迭代器

 SPL提供了5个迭代器接口：Traversable.Iterator.IteratorAggregate.OuterIterator ,RecurseiveIterator。 

使用IteratorAggregate接口

 class MyIterableClass implements IteratorAggregate{
 	
 	protected $arr;
 	
 	public function __construct(){
 		$this->arr=array(1,2,3);
 	}
 	
 	public function getIterator(){
 		return new ArrayIterator($this->arr);
 	}
 }
 
 foreach(new MyIterableClass() as $value){
 	echo $value."\n";
 }
输出如下

使用ArrayIterator迭代器

$arr=array('a','b','c');
$iterator=new ArrayIterator($arr);
foreach($iterator as $val){
	echo $val;
}

使用LimitIterator 迭代器

$arr=array(1,2,3,4,5,6,7,8);
$arrIterator=new ArrayIterator($arr);
$limitIterator=new LimitIterator($arrIterator,3,4);
foreach ($limitIterator as $number){
	echo $number;
}

使用AppendIterator迭代器

$arrFirst=new ArrayIterator(array(1,2,3));

$arrSecond=new ArrayIterator(array(4,5,6));

$iterator=new AppendIterator();
$iterator->append($arrFirst);
$iterator->append($arrSecond);

foreach($iterator as $number){
	echo $number;
}

高级的数组合并功能

$arrFirst=new ArrayIterator(array(1,2,3));

$arrSecond=new ArrayIterator(array(4,5,6));

$iterator=new AppendIterator();
$iterator->append(new LimitIterator($arrFirst,0,2));
$iterator->append(new LimitIterator($arrSecond,0,2));
print_r(iterator_to_array($iterator,false));

 

 

使用FilterIterator 迭代器

$arrFirst=new ArrayIterator(array(1,2,3));

$arrSecond=new ArrayIterator(array(4,5,6));

$iterator=new AppendIterator();
$iterator->append(new LimitIterator($arrFirst,0,2));
$iterator->append(new LimitIterator($arrSecond,0,2));
print_r(iterator_to_array($iterator,false));

使用一个基本的RegexIterator迭代器

$arr=array('apple','avocado','orange','pineapple');
$arrIterator=new ArrayIterator($arr);

$iterator=new RegexIterator($arrIterator,'/^a/');
print_r(iterator_to_array($iterator));