PHP对多维数组进行排序

Question

I am new to PHP and I am unsure as to why my code is not outputting. I have everything in place with no errors and everything seems correct. I am trying to output the names and dates in ascending order while using print_r() to verify the order. I would appreciate some guidance to this matter as I have no idea where I am going wrong.

$win = array('Name'=> 
                        array('Jane Doe ', 'Nash Patel ', 'Joe Public '), 
             'Date'=>
                        array('7 October 2015 ', '14 October 2014 ', '12 October 2016 '));

foreach($win as $element => $namedate) {
    echo '<strong>' . $element . '</strong><br>';
    foreach($namedate as $both) {
       echo $both . '<br/>';
    }
}

foreach($win as $c=>$key) {
        $sort_date[] = $key['Date'];
        $sort_name[] = $key['Name'];
    }

    array_multisort($sort_name, SORT_ASC, $sort_date, SORT_ASC, $win);
    print_r($win);

OUTPUT\\

Array ( [Date] => Array ( [0] => 7 October 2015 [1] => 14 October 2014 [2] => 12 October 2016 ) [Name] => Array ( [0] => Jane Doe [1] => Nash Patel [2] => Joe Public ) )

Answer 1

I've read the docs and it seems that

array_multisort($sort_name, SORT_ASC, $sort_date, SORT_ASC, $win);

means that $win will be sorted by name and date, but sorting by name has bigger priority over date.

Try adding more Jane Doe with different dates to see that they're sorted with date.

Answer 2

Because you say the arrays don't need to be sorted together here is how to split them and sort them separately.

$win = array('Name'=> 
                    array('Jane Doe ', 'Nash Patel ', 'Joe Public '), 
         'Date'=>
                    array('7 October 2015 ', '14 October 2014 ', '12 October 2016 '));


$dates = $win["Date"]; //split array
$names = $win["Name"]; //split array

usort($dates, "date_sort"); // custom sort on dates
asort($names); // sort names

var_dump($dates);
Var_dump($names);


function date_sort($a, $b) {
    return strtotime($a) - strtotime($b);
}

https://3v4l.org/kLjRh

Output:

array(3) {
  [0]=>
  string(16) "14 October 2014 "
  [1]=>
  string(15) "7 October 2015 "
  [2]=>
  string(16) "12 October 2016 "
}

 array(3) {
  [0]=>
  string(9) "Jane Doe "
  [2]=>
  string(11) "Joe Public "
  [1]=>
  string(11) "Nash Patel "
}