php 二维数组 根据show_type 的值 转成三维数组

Question

Array
(
    [0] => Array
        (
            [sunit] => 一年
            [map] => 114.298121,29.962919
            [show_type] => 1
            [litpic] => /uploads/userup/1/13M160936-ZM.jpg
            [title] => 桂乡大道单立柱
        )    [1] => Array
        (
            [sunit] => 一年
            [map] => 114.287299,29.970506
            [show_type] => 2
            [litpic] => /uploads/allimg/130826/1-130R6094S00-L.jpg
            [title] => 咸宁桂乡大道咸宁北收费站广告牌
        )    [2] => Array
        (
            [sunit] => 一年
            [map] => 114.287885,29.970592
            [show_type] => 2
            [litpic] => /uploads/allimg/130826/1-130R61042060-L.jpg
            [title] => 咸宁桂乡大道咸宁北收费站右旁广告牌
        )    [3] => Array
        (
            [sunit] => 月
            [map] => 114.292226,29.966466
            [show_type] => 1
            [litpic] => /uploads/allimg/130826/1-130R61501170-L.jpg
            [title] => 咸宁桂乡大道单立柱
        )
) 把这个二维数组 根据show_type 的值 转成三维数组 这个怎么实现的呢？？谢谢啦

Answer 1

foreach($ar as $r) $res[$r['show_type']][] = $r;print_r($res);