php怎么实现两个数组合并
数组一：
$a_array = Array ([0] => Array ([plan_id] => 1[ad_img_url] => http://www.adsload.com/assets/ad1.jpg)[1] => Array ([plan_id] => 2[ad_img_url] => http://www.adsload.com/assets/ad2.jpg)[2] => Array ([plan_id] => 3[ad_img_url] => http://www.adsload.com/assets/ad3.jpg))
数组二：
$b_array = Array ([0] => Array ([plan_id] => 1[ad_url] => http://www.baidu.com/)[1] => Array ([plan_id] => 2[ad_url] => http://www.baidu.com/)[2] => Array ([plan_id] => 3[ad_url] => http://www.baidu.com/))
合并后：
$ressult_array = Array ([0] => Array ([plan_id] => 1[ad_img_url] => http://www.adsload.com/assets/ad1.jpg[ad_url] => http://www.baidu.com/)[1] => Array ([plan_id] => 2[ad_img_url] => http://www.adsload.com/assets/ad2.jpg[ad_url] => http://www.baidu.com/)[2] => Array ([plan_id] => 3[ad_img_url] => http://www.adsload.com/assets/ad3.jpg[ad_url] => http://www.baidu.com/