| public static multisort ( array &$array, string | Closure | array $key, integer | array $direction = SORT_ASC, integer | array $sortFlag = SORT_REGULAR ) | ||
| $array | array | the array to be sorted. The array will be modified after calling this method. |
| $key | string | Closure | array | the key(s) to be sorted by. This refers to a key name of the sub-array elements, a property name of the objects, or an anonymous function returning the values for comparison purpose. The anonymous function signature should be: `function($item)`. To sort by multiple keys, provide an array of keys here. |
| $direction | integer | array | the sorting direction. It can be either `SORT_ASC` or `SORT_DESC`. When sorting by multiple keys with different sorting directions, use an array of sorting directions. |
| $sortFlag | integer | array | the PHP sort flag. Valid values include `SORT_REGULAR`, `SORT_NUMERIC`, `SORT_STRING`, `SORT_LOCALE_STRING`, `SORT_NATURAL` and `SORT_FLAG_CASE`. Please refer to [PHP manual](http://php.net/manual/en/function.sort.php) for more details. When sorting by multiple keys with different sort flags, use an array of sort flags. |
public static function multisort(&$array, $key, $direction = SORT_ASC, $sortFlag = SORT_REGULAR)
{
$keys = is_array($key) ? $key : [$key];
if (empty($keys) || empty($array)) {
return;
}
$n = count($keys);
if (is_scalar($direction)) {
$direction = array_fill(0, $n, $direction);
} elseif (count($direction) !== $n) {
throw new InvalidParamException('The length of $direction parameter must be the same as that of $keys.');
}
if (is_scalar($sortFlag)) {
$sortFlag = array_fill(0, $n, $sortFlag);
} elseif (count($sortFlag) !== $n) {
throw new InvalidParamException('The length of $sortFlag parameter must be the same as that of $keys.');
}
$args = [];
foreach ($keys as $i => $key) {
$flag = $sortFlag[$i];
$args[] = static::getColumn($array, $key);
$args[] = $direction[$i];
$args[] = $flag;
}
// This fix is used for cases when main sorting specified by columns has equal values
// Without it it will lead to Fatal Error: Nesting level too deep - recursive dependency?
$args[] = range(1, count($array));
$args[] = SORT_ASC;
$args[] = SORT_NUMERIC;
$args[] =& $array;
call_user_func_array('array_multisort', $args);
}