按一个键对对象数组进行排序和搜索

Question

$data = Array ( 
           [0] => stdClass Object ( [ID] => 1 [top_level] => gold [sub_level] => coal ) 
           [1] => stdClass Object ( [ID] => 3 [top_level] => bronze [sub_level] => dirt ) 
           [2] => stdClass Object ( [ID] => 4 [top_level] => silver [sub_level] => aluminum ) 
    )

使用PHP，我如何通过[sub_level]升序（或降序）来排序以产生以下内容？

Array ( 
       [0] => stdClass Object ( [ID] => 4 [top_level] => silver [sub_level] => aluminum ) 
       [1] => stdClass Object ( [ID] => 1 [top_level] => gold [sub_level] => coal ) 
       [2] => stdClass Object ( [ID] => 3 [top_level] => bronze [sub_level] => dirt )  
)

此外，搜索[sub_level]特定值的最有效方法是什么？

Answer 1

您可以使用usort。在函数中，比较所需的两个属性并返回适当的值。有关详细信息，请参阅suggested duplicate。