如何按PHP中的时间值对多维数组进行排序？

Question

I'm doing a school project and I have a multi-dimensional array having start_time and end_time of courses.

I already sorted the array by day, but I also want to sort the array by time. Such that the lowest start_time is the first element of the array.

This is how my array is at the moment:

Array ( 
       [0] => Array ( 
                     [courseID] => comp345
                     [lectureID] => ss
                     [day] => monday
                     [stime] => 18:20 
                     [etime] => 20:30 
                     [term] => winter 
                     [year] => 2014 
              )
       [1] => Array ( 
                     [courseID] => comp275 
                     [lectureID] => gg 
                     [day] => monday 
                     [stime] => 12:15 
                     [etime] => 15:16 
                     [term] => winter 
                     [year] => 2014
              )
)

I was wondering if there are any pre-defined functions to do that or if i need to create a new specific function for this task .

I can access the values of the start_time like this :

foreach ($array as $element)
{
  $start_time = (substr($element['stime'], 0, 5));
}

This will return the time in this format : 08:20

It works the same way as normal numbers when comparing such as :

08:20 < 10:15 = true

08:20 > 10:15 = false

Answer 1

PHP >= 5.5.0:

array_multisort(array_map('strtotime', array_column($array, 'stime')), SORT_ASC, $array);

PHP < 5.5.0:

foreach ($array as $k => $v) {
  $stime[$k] = strtotime($v['stime']);
}
array_multisort($stime, SORT_ASC, $array);