array中按照key排序的问题？

$test=array(60) {
 [0]=> object(stdClass)#14 (3) { ["id"]=> string(3) "609" ["title"]=> string(19) "Physical Mechanisms" ["publish_time"]=> string(10) "6 MAY 2016" }
 [1]=> object(stdClass)#14 (3) { ["id"]=> string(3) "610" ["title"]=> string(20) "Engineering Substrate" ["publish_time"]=> string(10) "2 MAY 2016" }
  ...}
 

根据publish_time对$test进行排序，怎么做？请教！

回复内容：

$test=array(60) {
 [0]=> object(stdClass)#14 (3) { ["id"]=> string(3) "609" ["title"]=> string(19) "Physical Mechanisms" ["publish_time"]=> string(10) "6 MAY 2016" }
 [1]=> object(stdClass)#14 (3) { ["id"]=> string(3) "610" ["title"]=> string(20) "Engineering Substrate" ["publish_time"]=> string(10) "2 MAY 2016" }
  ...}
 

根据publish_time对$test进行排序，怎么做？请教！

可以用php函数 usort 自定义排序

publish_time) < strtotime($a->publish_time) ) {
        return -1;
    } else if( strtotime($a->publish_time) > strtotime($a->publish_time) ){
        return 1;
    } else {
        return 0;
    }
}

usort($arr, '_usort');