Php 递归迭代器和嵌套递归数组迭代器
我一直在使用递归ArrayInterators将嵌套对象处理为树。下面的代码让我很困扰,因为结果只返回了我期望的一些值。基本上,根节点似乎永远不会被迭代。我有一种感觉,我只是盯着它看了有点太久,但我想确保我在正确的轨道上与这一点Php 递归迭代器和嵌套递归数组迭代器,php,spl,recursiveiterator,Php,Spl,Recursiveiterator,我一直在使用递归ArrayInterators将嵌套对象处理为树。下面的代码让我很困扰,因为结果只返回了我期望的一些值。基本上,根节点似乎永远不会被迭代。我有一种感觉,我只是盯着它看了有点太久,但我想确保我在正确的轨道上与这一点 class Container extends \RecursiveArrayIterator { protected $_alias; public function __construct( $alias = null ) {
class Container extends \RecursiveArrayIterator
{
protected $_alias;
public function __construct( $alias = null )
{
if( is_null( $alias ) )
{
$alias = uniqid( 'block_' );
}
$this->_alias = $alias;
}
public function getAlias()
{
return $this->_alias;
}
}
try
{
$root = new Container( 'root_level' );
$block = new Container( 'first_level' );
$child = new Container( 'second_level' );
$child_of_child_a = new Container( 'third_level_a' );
$child_of_child_b = new Container( 'third_level_b' );
$child->append( $child_of_child_a );
$child->append( $child_of_child_b );
$child_of_child_a->append( new Container );
$child_of_child_a->append( new Container );
$block->append( $child );
$root->append( $block );
$storage = new \RecursiveIteratorIterator( $root, RecursiveIteratorIterator::SELF_FIRST );
foreach( $storage as $key => $value )
{
print_r( str_repeat( ' ', $storage->getDepth() * 4 ) . $value->getAlias() . PHP_EOL );
}
}
catch( \Exception $e )
{
var_dump( $e->getMessage() );
}
结果是
first_level
second_level
third_level_a
block_51f98b779c107
block_51f98b779c124
third_level_b
根节点在哪里
答复
斯文的回答刺激了我过度工作的大脑,使我正确地处理了这个问题。这是我最后一段成功的代码,以防其他人尝试类似的事情
class OuterContainer extends \ArrayIterator
{
}
class Container extends \ArrayIterator
{
protected $_alias;
public function __construct( $alias = null )
{
if( is_null( $alias ) )
{
$alias = uniqid( 'container_' );
}
$this->_alias = $alias;
}
public function getAlias()
{
return $this->_alias;
}
}
try
{
$c1 = new Container( 'Base' );
$c1_c1 = new Container( 'Base > 1st Child' );
$c1_c2 = new Container( 'Base > 2nd Child' );
$c1_c1_c1 = new Container( 'Base > 1st Child > 1st Child' );
$c1_c1->append( $c1_c1_c1 );
$c1->append( $c1_c1 );
$c1->append( $c1_c2 );
$outer_container = new OuterContainer;
$outer_container->append( $c1 );
$storage = new \RecursiveIteratorIterator( new \RecursiveArrayIterator( $outer_container ), RecursiveIteratorIterator::SELF_FIRST );
foreach( $storage as $key => $value )
{
print_r( $value->getAlias() . PHP_EOL );
}
}
catch( \Exception $e )
{
var_dump( $e->getMessage() );
}
根节点不存在,因为您没有正确使用RecursiveArrayIterator 它的用途是在任何级别和结构中拥有一个包含多个子数组的数组,并将该数组放入递归ArrayIterator的一个实例中,然后迭代所有内容,将其放入递归Iterator中 这样,整个数组,包括它的顶层,都将被迭代 因为您滥用了RecursiveArrayIterator作为信息的载体,所以顶级对象不会被迭代 提出了一个简单的例子,有一些不好的地方,但说明了原则:
$root = array( 'root_level' );
$block = array( 'first_level' );
$child = array( 'second_level' );
$child_of_child_a = array( 'third_level_a' );
$child_of_child_b = array( 'third_level_b' );
$child[] = $child_of_child_a;
$child[] = $child_of_child_b ;
$child_of_child_a[] = array('');
$child_of_child_a[] = array('');
$block[] = $child;
$root[] = $block ;
$storage = new \RecursiveIteratorIterator( new \RecursiveArrayIterator($root), RecursiveIteratorIterator::SELF_FIRST );
var_dump($root);
foreach ($storage as $key=>$value) {
echo $key.": ".$value."\n";
}
结果输出:
array(2) {
[0] =>
string(10) "root_level"
[1] =>
array(2) {
[0] =>
string(11) "first_level"
[1] =>
array(3) {
[0] =>
string(12) "second_level"
[1] =>
array(1) {
...
}
[2] =>
array(1) {
...
}
}
}
}
0: root_level
1: Array
0: first_level
1: Array
0: second_level
1: Array
0: third_level_a
2: Array
0: third_level_b
它的输出并不完全相同,但我的观点是,您可以在结构上进行迭代,而不必让每个节点都成为递归ArrayIterator的实例。你可以添加任何东西,要么是数组,要么是充当数组的对象,要么是可以有效地进行迭代的对象。说真的,
var\u dump($root)
:)?这让事情变得更清楚了。非常感谢。不过,我真正想弄明白的是使用一些Spl迭代器以类似方式嵌套对象的最佳方法。