PHP recursion: How to create a recursion in php

问题

I have a little problem with a recursion in php. I have read many articles but the solution doesn't come.

I have this array:

[59] => Array
    (
        [ID] => REL000000
        [Name] => RELIGIONE / Generale
        [Description] => 
        [IdParent] => 
    )

[799] => Array
    (
        [ID] => REL102000
        [Name] => RELIGIONE / Teologia
        [Description] => 
        [IdParent] => REL000000
    )

[800] => Array
    (
        [ID] => REL068000
        [Name] => RELIGIONE / Teosofia
        [Description] => 
        [IdParent] => REL000000
    )

[801] => Array
    (
        [ID] => REL103000
        [Name] => RELIGIONE / Universalismo Unitario
        [Description] => 
        [IdParent] => REL000000
    )

[802] => Array
    (
        [ID] => REL034000
        [Name] => RELIGIONE / FestivitÃ  / Generale
        [Description] => 
        [IdParent] => REL000000
    )

I would like to create a hierarchical tree where the IdParent field match with the ID field.

Does anybody help me?

thanks

回答1:

Use the & operator:

$array[$id_child]['parent'] = &$array[$id_parent];

and also:

$array[$id_parent]['children'][] = &$array[$id_child];

回答2:

a[59]['IdParent'] = a[59]['ID'];

doesn't that work as per your question ?

回答3:

// There is a function maybe useful
/**
 * get all sub
 *
 * @author Tom
 * @date   2017-12-21
 * @param  array   $array  The array
 * @param  int|str $topId  the the top ID
 * @param  int     $lev    the the lev(It's ver useful in some case)
 * @return array   $result all sub data 
 */
function getLower($array, $topId, $lev = 0) {
    $result = [];
    foreach ($array as $key => $value) {
        if ($value['IdParent'] == $topId) {
            $value['lev'] = $lev; // the level
            $result[]     = $value;
            $result       = array_merge($result, getLower($array, $value['ID'], $lev + 1));
        }
    }
    return $result;
}

来源：https://stackoverflow.com/questions/4931080/php-recursion-how-to-create-a-recursion-in-php

标签

php

recursion