一个分类数组，树形返回，下级分类数据存放在subcat里面，一共有三级分类，现在需要输入一个分类id，直接返回分类的名称，如：一级分类》二级分类》三级分类。
核心函数：
/**
* 返回分类层级,如：一级分类》二级分类》三级分类
* @param $categories array 树形分类
* @param $categoryId int 分类ID的值
* @param $idKey string 分类ID的名称
* @param $subcatKey string 二级分类的键名
* @param $name string 需要返回的分类名称
* @param $div string 分割字符串
* @return mixed|string|null
*/
function getCategoryName($categories, $categoryId, $idKey = 'id', $subcatKey = 'subcat', $name = 'name', $div = ' » ')
{
foreach ($categories as $category) {
if ($category[$idKey] == $categoryId) {
return $category[$name];
}
if (isset($category[$subcatKey])) {
$result = getCategoryName($category[$subcatKey], $categoryId);
if ($result !== null) {
return $category[$name] . $div . $result;
}
}
}
return null;
}调用实例()：
$category = $categorys = array( 0 => array( 'id' => 55, 'name' => '产品中心', 'pid' => 0, 'url' => '/index/index/product', 'subcat' => array( 0 => array( 'id' => 60, 'name' => '产品大类2', 'pid' => 55, 'url' => '/index/index/product_detail', 'subcat' => array( 0 => array( 'id' => 61, 'name' => '产品小类1', 'pid' => 60, 'url' => '/index/index/product_detail', ), 1 => array( 'id' => 62, 'name' => '产品小类2', 'pid' => 60, 'url' => '/index/index/product_detail', ), ), ), 1 => array( 'id' => 63, 'name' => '产品大类3', 'pid' => 55, 'url' => '/index/index/product_detail', 'subcat' => array( 0 => array( 'id' => 64, 'name' => '名贵茶品', 'pid' => 63, 'url' => '/index/index/product/cid/abc', ), ), ), 2 => array( 'id' => 65, 'name' => '产品大类5', 'pid' => 55, 'url' => '/index/index/product_detail', ), 3 => array( 'id' => 56, 'name' => '产品大类1', 'pid' => 55, 'url' => '/index/index/product_detail', 'subcat' => array( 0 => array( 'id' => 57, 'name' => '产品小类1', 'pid' => 56, 'url' => '/index/index/product_detail', ), 1 => array( 'id' => 58, 'name' => '产品小类2', 'pid' => 56, 'url' => '/index/index/product_detail', ), 2 => array( 'id' => 59, 'name' => '产品小类3', 'pid' => 56, 'url' => '/index/index/product_detail', ), ), ), ), ), ); //调用 $value['category_name'] = getCategoryName($categorys, $value['category_id']);
效果：
