PHP無限級樹形結構演算法(遞迴和引用)
阿新 • • 發佈:2018-12-02
測試陣列
$array = [
['id' => 1, 'pid' => 0, 'name' => '這是主類'],
['id' => 2, 'pid' => 0, 'name' => '這是主類'],
['id' => 3, 'pid' => 1, 'name' => '父級為1子類'],
['id' => 4, 'pid' => 2, 'name' => '父級為2子類'],
['id' => 5, 'pid' => 3, 'name' => '父級為3子類' ],
];
一、遞迴演算法
function tree($array, $pid)
{
$tree = array();
foreach ($array as $key => $value) {
if ($value['pid'] == $pid) {
$value['child'] = tree($array, $value['id']);
if (!$value['child']) {
unset($value['child']);
}
$tree [] = $value;
}
}
return $tree;
}
echo "<pre>" . print_r(tree($array, 1), 1) . "</pre>";
二、陣列引用
function generateTree($rows, $id = 'id', $pid = 'pid')
{
$items = array();
foreach ($rows as $row) {
$items[$row[$id]] = $row;
}
foreach ($items as $item ) {
$items[$item[$pid]]['son'][$item[$id]] = &$items[$item[$id]];
}
return isset($items[0]['son']) ? $items[0]['son'] : array();
}
echo "<pre>" . print_r(generateTree($array), 1) . "</pre>";
看不懂的萌新可以使用PhpStorm在輸出那兒打斷點進行除錯哈。