Examples of two unlimited classification methods in php, two classification examples in php_PHP tutorial

Examples of two infinite classification methods in php, two examples of classification in php

1. Recursive method
Copy code The code is as follows:
$items = array(
array('id'=>1,'pid'=>0,'name'=>'Level 11'),
array('id'=>2,'pid'=>0,'name'=>'Level 12'),
array('id'=>3,'pid'=>1,'name'=>'Level 21'),
array('id'=>4,'pid'=>3,'name'=>'Level 3 31'),
array('id'=>5,'pid'=>1,'name'=>'Level 22'),
array('id'=>6,'pid'=>3,'name'=>'Level 32'),
array('id'=>7,'pid'=>6,'name'=>'Level 41'),
);
$i = 0;
function formatTree($arr, $pid = 0){
$tree = array();
$temp = array();
global $i;
if($arr){
foreach($arr as $k=>$v){
if($v['pid'] == $pid){//
$temp = formatTree($arr, $v['id']);
$temp && $v['son'] = $temp;
$tree[] = $v;
}
}
}
return $tree;
}
print_r(formatTree($items));

2. Non-recursive method
Copy code The code is as follows:
function genTree($items) {
$tree = array(); //Formatted tree
foreach ($items as $item)
If (isset($items[$item['pid']])){
$items[$item['pid']]['son'][] = &$items[$item['id']];
}
        else{
               $tree[] = &$items[$item['id']];
}
Return $tree;
}

$items = array(
1 => array('id' => 1, 'pid' => 0, 'name' => 'Level 11'),
2 => array('id' => 2, 'pid' => 1, 'name' => 'Level 21'),
3 => array('id' => 3, 'pid' => 1, 'name' => 'Level 23'),
4 => array('id' => 4, 'pid' => 9, 'name' => 'Level 3 31'),
5 => array('id' => 5, 'pid' => 4, 'name' => 'Level 43'),
6 => array('id' => 6, 'pid' => 9, 'name' => 'Level 32'),
7 => array('id' => 7, 'pid' => 4, 'name' => 'Level 41'),
8 => array('id' => 8, 'pid' => 4, 'name' => 'Level 4 42'),
9 => array('id' => 9, 'pid' => 1, 'name' => 'Level 25'),
10 => array('id' => 10, 'pid' => 11, 'name' => 'Level 22'),
11 => array('id' => 11, 'pid' => 0, 'name' => 'Level 12'),
12 => array('id' => 12, 'pid' => 11, 'name' => 'Level 24'),
13 => array('id' => 13, 'pid' => 4, 'name' => 'Level 44'),
14 => array('id' => 14, 'pid' => 1, 'name' => 'Level 26'),
15 => array('id' => 15, 'pid' => 8, 'name' => 'Level 5 51'),
16 => array('id' => 16, 'pid' => 8, 'name' => 'Level 5 52'),
17 => array('id' => 17, 'pid' => 8, 'name' => 'Level 5 53'),
18 => array('id' => 18, 'pid' => 16, 'name' => 'Level 6 64'),
);
print_r(genTree($items));

http://www.bkjia.com/PHPjc/987894.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/987894.htmlTechArticlePHP two infinite classification methods examples, PHP two classification examples 1. Recursive method Copy the code The code is as follows: $items = array( array('id'=1,'pid'=0,'name'='Level 11'), array('id'=2,'pid'=...