从嵌套数组中查找最新日期

Question

I have a Multilevel Array ( See array structure picture below ) and I need to get the sub-nested array with the higher date value .

I was wondering if there is a straight forward way to sort sub-nested arrays by date value or get the highest date value ?

Array Map

Answer 1

To do that, usort() function will be useful:

usort($rgData, function($rgX, $rgY)
{
   $x = strtotime($rgX['date']);
   $y = strtotime($rgY['date']);
   return $x<$y?-1:$x!=$y;
});
//var_dump($rgData);

if you want to get highest value, then it will be ['date'] key of last element after doing the sort above.

Edit: if you're sure that format will be exactly same as on picture always, you can use direct string comparison via strcmp (that would be probably faster)

Answer 2

How about using usort() :

$input = array(
    array('date' => '2013-09-11 13:08:40 +0000'),
    array('date' => '2013-09-11 13:09:17 +0000'));

usort($input, function(array $a, array $b) {
    $aTimestamp = strtotime($a['date']);
    $bTimestamp = strtotime($b['date']);

    if($aTimestamp == $bTimestamp) return 0;
    return $aTimestamp < $bTimestamp;
});

print_r($input); //$input[0] has the latest date value