PHP で多次元配列をソートする方法

function make_comparer() {
    // Normalize criteria up front so that the comparer finds everything tidy
    $criteria = func_get_args();
    foreach ($criteria as $index => $criterion) {
        $criteria[$index] = is_array($criterion)
            ? array_pad($criterion, 3, null)
            : array($criterion, SORT_ASC, null);
    }

    return function($first, $second) use (&$criteria) {
        foreach ($criteria as $criterion) {
            // How will we compare this round?
            list($column, $sortOrder, $projection) = $criterion;
            $sortOrder = $sortOrder === SORT_DESC ? -1 : 1;

            // If a projection was defined project the values now
            if ($projection) {
                $lhs = call_user_func($projection, $first[$column]);
                $rhs = call_user_func($projection, $second[$column]);
            }
            else {
                $lhs = $first[$column];
                $rhs = $second[$column];
            }

            // Do the actual comparison; do not return if equal
            if ($lhs < $rhs) {
                return -1 * $sortOrder;
            }
            else if ($lhs > $rhs) {
                return 1 * $sortOrder;
            }
        }

        return 0; // tiebreakers exhausted, so $first == $second
    };
}

$data = array(
    array('zz', 'name' => 'Jack', 'number' => 22, 'birthday' => '12/03/1980'),
    array('xx', 'name' => 'Adam', 'number' => 16, 'birthday' => '01/12/1979'),
    array('aa', 'name' => 'Paul', 'number' => 16, 'birthday' => '03/11/1987'),
    array('cc', 'name' => 'Helen', 'number' => 44, 'birthday' => '24/06/1967'),
);

usort($data, make_comparer('name'));

usort($data, make_comparer(0)); // 0 = first numerically indexed column

usort($data, make_comparer('number', 0));

0 => the column name to sort on (mandatory)
1 => either SORT_ASC or SORT_DESC (optional)
2 => a projection function (optional)

usort($data, make_comparer(['name', SORT_DESC]));

usort($data, make_comparer(['number', SORT_DESC], ['name', SORT_DESC]));

usort($data, make_comparer('birthday'));

usort($data, make_comparer(['birthday', SORT_ASC, 'date_create']));

usort($data, make_comparer(
    ['number', SORT_DESC],
    ['birthday', SORT_ASC, 'date_create']
));

foreach ($mdarray as $key => $row) {
    // replace 0 with the field's index/key
    $dates[$key]  = $row[0];
}

array_multisort($dates, SORT_DESC, $mdarray);

array_multisort(array_column($mdarray, 0), SORT_DESC, $mdarray);

class TableSorter {
  protected $column;
  function __construct($column) {
    $this->column = $column;
  }
  function sort($table) {
    usort($table, array($this, 'compare'));
    return $table;
  }
  function compare($a, $b) {
    if ($a[$this->column] == $b[$this->column]) {
      return 0;
    }
    return ($a[$this->column] < $b[$this->column]) ? -1 : 1;
  }
}

$sorter = new TableSorter(0); // sort by first column
$mdarray = $sorter->sort($mdarray);

/**
 * Sorting array of associative arrays - multiple row sorting using a closure.
 * See also: http://the-art-of-web.com/php/sortarray/
 *
 * @param array $data input-array
 * @param string|array $fields array-keys
 * @license Public Domain
 * @return array
 */
function sortArray( $data, $field ) {
    $field = (array) $field;
    uasort( $data, function($a, $b) use($field) {
        $retval = 0;
        foreach( $field as $fieldname ) {
            if( $retval == 0 ) $retval = strnatcmp( $a[$fieldname], $b[$fieldname] );
        }
        return $retval;
    } );
    return $data;
}

/* example */
$data = array(
    array( "firstname" => "Mary", "lastname" => "Johnson", "age" => 25 ),
    array( "firstname" => "Amanda", "lastname" => "Miller", "age" => 18 ),
    array( "firstname" => "James", "lastname" => "Brown", "age" => 31 ),
    array( "firstname" => "Patricia", "lastname" => "Williams", "age" => 7 ),
    array( "firstname" => "Michael", "lastname" => "Davis", "age" => 43 ),
    array( "firstname" => "Sarah", "lastname" => "Miller", "age" => 24 ),
    array( "firstname" => "Patrick", "lastname" => "Miller", "age" => 27 )
);

$data = sortArray( $data, 'age' );
$data = sortArray( $data, array( 'lastname', 'firstname' ) );

function sort_multi_array ($array, $key)
{
  $keys = array();
  for ($i=1;$i

function cmp($a, $b)
{
$p1 = $a['price'];
$p2 = $b['price'];
return (float)$p1 > (float)$p2;
}
uasort($my_array, "cmp");

// a sorter class
//  php4 and php5 compatible
class Sorter {

  var $sort_fields;
  var $backwards = false;
  var $numeric = false;

  function sort() {
    $args = func_get_args();
    $array = $args[0];
    if (!$array) return array();
    $this->sort_fields = array_slice($args, 1);
    if (!$this->sort_fields) return $array();

    if ($this->numeric) {
      usort($array, array($this, 'numericCompare'));
    } else {
      usort($array, array($this, 'stringCompare'));
    }
    return $array;
  }

  function numericCompare($a, $b) {
    foreach($this->sort_fields as $sort_field) {
      if ($a[$sort_field] == $b[$sort_field]) {
        continue;
      }
      return ($a[$sort_field] < $b[$sort_field]) ? ($this->backwards ? 1 : -1) : ($this->backwards ? -1 : 1);
    }
    return 0;
  }

  function stringCompare($a, $b) {
    foreach($this->sort_fields as $sort_field) {
      $cmp_result = strcasecmp($a[$sort_field], $b[$sort_field]);
      if ($cmp_result == 0) continue;

      return ($this->backwards ? -$cmp_result : $cmp_result);
    }
    return 0;
  }
}

/////////////////////
// usage examples

// some starting data
$start_data = array(
  array('first_name' => 'John', 'last_name' => 'Smith', 'age' => 10),
  array('first_name' => 'Joe', 'last_name' => 'Smith', 'age' => 11),
  array('first_name' => 'Jake', 'last_name' => 'Xample', 'age' => 9),
);

// sort by last_name, then first_name
$sorter = new Sorter();
print_r($sorter->sort($start_data, 'last_name', 'first_name'));

// sort by first_name, then last_name
$sorter = new Sorter();
print_r($sorter->sort($start_data, 'first_name', 'last_name'));

// sort by last_name, then first_name (backwards)
$sorter = new Sorter();
$sorter->backwards = true;
print_r($sorter->sort($start_data, 'last_name', 'first_name'));

// sort numerically by age
$sorter = new Sorter();
$sorter->numeric = true;
print_r($sorter->sort($start_data, 'age'));