PHP使用Usort对多维数组进行排序

Question

I've seen similar questions, I simply do not understand the answers. Hopefully if I ask specifically about my code something will click. I've been stuck for some time and would really appreciate the help.

I have an array: foreach ($showresult as $display) { $display_result[] = array ('parkid' =>$display['parkid'],

                 'trailsys' =>$display['trailsys'],

                         'trailset' =>$display['trailset'],

                         'name' =>$display['name'], 

                         'description' =>$display['description'], 

                         'url' =>$display['url'], 

                                 'ldes' =>$display['ldes'],

                                 'ltxt' =>$display['ltxt'],

                         'address' =>$display['address'], 

                         'city' =>$display['city'], 

                         'zip' =>$display['zip'], 

                         'phone' =>$display['phone'], 

                         'pos' =>$display['pos'],   

                         'T1' => $display['systemname'],

                 'T2'=> $display['name']);

 {                           'state' =>$display['state'], 

Every item in the array has a value in T1. T2 can have a value, or it can be 0. I want to alphabetize the list by T1. In some cases, there will be three or four entries where T1 is the same, then I want to alphabetize those by T2. I'm stumped.

Please help.

Answer 1

You should try with usort() function ( http://www.php.net/usort ). It allows you to sort array by custom function. So, in your case it would be something like:

<?
  usort($array,function($a,$b) {
    if ($a['T1'] < $b['T1']) return -1;
    elseif ($a['T1'] > $b['T1']) return 1;
    else {
      if ($a['T2'] < $b['T2']) return -1;
      elseif ($a['T2'] > $b['T2']) return 1;
      else return 0;
    }
  });
?>

You could check it out and adjust to your needs.

Let me know if this works for you.