PHP - 按月和年排序数组

Question

这是我的阵列:

$ar = array( 
 'Jan-2016' => 1,
 'Feb-2016' => 2,
 'Mar-2016' => 3,  
 'Apr-2016' => 4,
 'May-2016' => 4,
 'Jun-2016' => 4,
 'Jul-2016' => 4,
 'Aug-2016' => 4,
 'Sep-2016' => 4,
 'Oct-2016' => 4,
 'Nov-2016' => 4,
 'Dec-2016' => 4,
 'Jan-2015' => 1,
 'Mar-2015' => 1);

我想按月和年对这个数组进行排序.我试过下面的代码:

ksort($ar);

但我不能像我预期的那样得到结果.

我需要结果如下面的数组:

$ar = array(
 'Jan-2015' => 1,
 'Mar-2015' => 1,
 'Jan-2016' => 1,
 'Feb-2016' => 2,
 'Mar-2016' => 3,  
 'Apr-2016' => 4,
 'May-2016' => 4,
 'Jun-2016' => 4,
 'Jul-2016' => 4,
 'Aug-2016' => 4,
 'Sep-2016' => 4,
 'Oct-2016' => 4,
 'Nov-2016' => 4,
 'Dec-2016' => 4);

Answer 1

uksort 是正确的功能:

uksort($ar, function($a1, $a2) {
        $time1 = strtotime($a1);
        $time2 = strtotime($a2);

        return $time1 - $time2;
    });

print_r($ar);