php教程

RecursiveIteratorIterator::__construct

(PHP 5 >= 5.1.3, PHP 7)

RecursiveIteratorIterator::__constructConstruct a RecursiveIteratorIterator

说明

public RecursiveIteratorIterator::__construct ( Traversable $iterator [, int $mode = RecursiveIteratorIterator::LEAVES_ONLY [, int $flags = 0 ]] )

Creates a RecursiveIteratorIterator from a RecursiveIterator.

参数

iterator

The iterator being constructed from. Either a RecursiveIterator or IteratorAggregate.

mode

Optional mode. Possible values are

  • RecursiveIteratorIterator::LEAVES_ONLY - The default. Lists only leaves in iteration.
  • RecursiveIteratorIterator::SELF_FIRST - Lists leaves and parents in iteration with parents coming first.
  • RecursiveIteratorIterator::CHILD_FIRST - Lists leaves and parents in iteration with leaves coming first.

flags

Optional flag. Possible values are RecursiveIteratorIterator::CATCH_GET_CHILD which will then ignore exceptions thrown in calls to RecursiveIteratorIterator::getChildren().

返回值

没有返回值。

范例

Example #1 Iterating a RecursiveIteratorIterator

<?php
$array 
= array(
    array(
        array(
            array(
                
'leaf-0-0-0-0',
                
'leaf-0-0-0-1'
            
),
            
'leaf-0-0-0'
        
),
        array(
            array(
                
'leaf-0-1-0-0',
                
'leaf-0-1-0-1'
            
),
            
'leaf-0-1-0'
        
),
        
'leaf-0-0'
    
)
);

$iterator = new RecursiveIteratorIterator(
    new 
RecursiveArrayIterator($array),
    
$mode
);
foreach (
$iterator as $key => $leaf) {
    echo 
"$key => $leaf"PHP_EOL;
}
?>

Output with $mode = RecursiveIteratorIterator::LEAVES_ONLY

0 => leaf-0-0-0-0
1 => leaf-0-0-0-1
0 => leaf-0-0-0
0 => leaf-0-1-0-0
1 => leaf-0-1-0-1
0 => leaf-0-1-0
0 => leaf-0-0

Output with $mode = RecursiveIteratorIterator::SELF_FIRST

0 => Array
0 => Array
0 => Array
0 => leaf-0-0-0-0
1 => leaf-0-0-0-1
1 => leaf-0-0-0
1 => Array
0 => Array
0 => leaf-0-1-0-0
1 => leaf-0-1-0-1
1 => leaf-0-1-0
2 => leaf-0-0

Output with $mode = RecursiveIteratorIterator::CHILD_FIRST

0 => leaf-0-0-0-0
1 => leaf-0-0-0-1
0 => Array
1 => leaf-0-0-0
0 => Array
0 => leaf-0-1-0-0
1 => leaf-0-1-0-1
0 => Array
1 => leaf-0-1-0
1 => Array
2 => leaf-0-0
0 => Array

User Contributed Notes

Tom 06-Jan-2011 01:13
Note: the missing documentation of the argument list for this constructor is currently as follows (according to source code).

Param iter: see RecursiveIterator

Param mode:
- LEAVES_ONLY = (default) only iterate leaves
- SELF_FIRST = iterate parents prior to children
- CHILD_FIRST = iterate children prior to parents

Param flags:
- CATCH_GET_CHILD = ignore exceptions in getChildren() call
Matt Creenan 05-Mar-2010 09:39
Note that LEAVES_ONLY, SELF_FIRST and CHILD_FIRST do not work by themselves.

They are class constants so you need to use RecursiveIteratorIterator::LEAVES_ONLY, etc.

CopyRight © 2008-2022 verySource.Com All Rights reserved. 京ICP备17048824号-1 京公网安备:11010502034788