3 ways to implement unlimited classification in PHP (summary)

This article brings you three implementation methods (summary) of unlimited classification in PHP. It has certain reference value. Friends in need can refer to it. I hope it will be helpful to you.

Infinite classification means that starting from the highest classification, each sub-category can be divided into several sub-categories of its own, which can be divided all the time, which is called infinite classification;

The following is the classification Examples of Infinitus classification of provinces, cities and counties. The database is as shown in the figure:

# The code example is as follows:

/**
 * @Description: 无限极分类一
 * @Author: Yang
 * @param $data  数据库数据
 * @param int $parent_id   父级ID
 * @return array
 */
function getTree1($data, $parent_id = 0)
{
    $tree = array();
    foreach ($data as $k => $v) {
        if ($v["parent_id"] == $parent_id) {
            unset($data[$k]);
            if (!empty($data)) {
                $children = getCategory($data, $v["id"]);
                if (!empty($children)) {
                    $v["_child"] = $children;
                }
            }
            $tree[] = $v;
        }
    }
    return $tree;
}


/**
 * @Description: 无限极分类二
 * @Author: Yang
 * @param $data   数据库数据
 * @param int $parent_id  父级ID
 * @param int $level  等级
 * @return array
 */
function getTree2($data, $parent_id = 0, $level = 0)
{
    static $tree = array();
    foreach ($data as $k => $v) {
        if ($v["parent_id"] == $parent_id) {
            $v["level"] = $level;
            $tree[] = $v;
            getTree($data, $v["id"], $level + 1);
        }
    }
    return $tree;
}

/**
 * @Description: 无限分类三：面包屑导航
 * @Author: Yang
 * @param $data  数据库数据
 * @param $id    分类ID
 * @return array
 */
function getCrumbsBar($data, $id) {
    static $tree = array();
    foreach ($data as $k => $v) {
        if ($v["id"] == $id) {
            getCrumbsBar($data, $v["parent_id"]);
            $tree[] = $v;
        }
    }
    return $tree;
}

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