TP框架封装无限极分类

<?php
namespace Admin\Model;
use Think\Model;

class CatModel extends Model{
	protected $cats = array();
	public function __construct(){
		parent::__construct();
		$this->cats = $this->select();
	}

	public function getTree($parent_id = 0,$lev = 0){
		$tree = array();		//声明一个数组 方便把循环出来的值保存起来
		foreach($this->cats as $c){
			if($c['parent_id'] == $parent_id){	//把parent_id为0的栏目先取出
				$tree[] = $c;		//每循环一次就把父parent_id和子parent_id对应值的保存起来
				$tree = array_merge($tree,$this->getTree($c['cat_id'],$lev+1));	//把$c下的cat_id放在函数再循环一次 为了$tree在循环里不会后者覆盖前者   用array_merge函数拼接数组
			}
		}
		return $tree;
	}
}