Sort Array from object

I have an object and store it in an array. However, when outputting the names from the object, I want to sort them by ‘is_main’. Thereby ‘is_main’ with the value 1 should always be in the first place and then ‘is_main’ with the value 0. Here is the Object

array(2){
   [
      1
   ]=> object(stdClass)#3729 (22){
    [
        "id_teacher"
     ]=> string(1)"2"[
        "firstname"
     ]=> string(6)"John"[
        "lastname"
     ]=> string(8)"Doe"[
        "is_main"
     ]=> string(1)"0"
   }[
      2
   ]=> object(stdClass)#3723 (22){
      [
         "id_teacher"
      ]=> string(1)"2"[
         "firstname"
      ]=> string(6)"John"[
         "lastname"
      ]=> string(8)"Brown"[
         "is_main"
      ]=> string(1)"1"
   }
}

And my PHP Code:

$storage = array();
foreach($data->class_teacher_arr[$item->id_class] as $reference) {
    $storage[] = $reference->firstname . ' ' . $reference->lastname . ' ' . $reference->is_main;
}
echo implode('<br/>', $storage);

I hope that someone can help me by this problem.

Answer

You can use usort with a callback defining what you’re looking for in the sort function.

$teachers = $data->class_teacher_arr[$item->id_class];
usort($teachers, function ($teacher) {
    return isset($teacher->is_main) && !$teacher->is_main;
});

$storage = array();
foreach($teachers as $reference) {
    $storage[] = $reference->firstname . ' ' . $reference->lastname . ' ' . $reference->is_main;
}
echo implode('<br/>', $storage);

If the value is_main is set and is true(equals 1), it will go to the top of the array and once you echo out your storage variable, you will see all of the is_main teachers at the top.

Check out this documentation for callback sorting of arrays.

https://www.php.net/manual/en/function.usort.php