array_multisort

Sort multiple or multi-dimensional arrays

true **array_multisort** array $array1 mixed $array1_sort_order mixed $array1_sort_flags mixed $rest

can be used to sort several

arrays at once, or a multi-dimensional array by one or more dimensions. array_multisort

Associative () keys will be maintained, but numeric keys will be re-indexed. string

array1 An being sorted. array

array1_sort_order The order used to sort the previous argument. Either to sort ascendingly or to sort descendingly. array``SORT_ASC``SORT_DESC

   This argument can be swapped with 
   or omitted entirely, in which case  is assumed.
  `array1_sort_flags``SORT_ASC`

array1_sort_flags Sort options for the previous argument: array

   Sorting type flags:
   
  - - compare items normally          (don't change types)`SORT_REGULAR`

- compare items numericallySORT_NUMERIC
- compare items as stringsSORT_STRING
- compare items as strings, based on the current locale. It uses the locale, which can be changed using SORT_LOCALE_STRING``setlocale
- compare items as strings using "natural ordering" like SORT_NATURAL``natsort
- can be combined (bitwise OR) with or to sort strings case-insensitively SORT_FLAG_CASE``SORT_STRING``SORT_NATURAL
  
  This argument can be swapped with or omitted entirely, in which case is assumed. array1_sort_order``SORT_REGULAR

restMore arrays, optionally followed by sort order and flags. Only elements corresponding to equivalent elements in previous arrays are compared. In other words, the sort is lexicographical.

return.true.always

Voorbeeld: Sorting multiple arrays

<?php
$ar1 = array(10, 100, 100, 0);
$ar2 = array(1, 3, 2, 4);
array_multisort($ar1, $ar2);

var_dump($ar1);
var_dump($ar2);
?>

In this example, after sorting, the first array will contain 0, 10, 100, 100. The second array will contain 4, 1, 2, 3. The entries in the second array corresponding to the identical entries in the first array (100 and 100) were sorted as well.

array(4) {
  [0]=> int(0)
  [1]=> int(10)
  [2]=> int(100)
  [3]=> int(100)
}
array(4) {
  [0]=> int(4)
  [1]=> int(1)
  [2]=> int(2)
  [3]=> int(3)
}

Voorbeeld: Sorting multi-dimensional array

<?php
$ar = array(
       array("10", 11, 100, 100, "a"),
       array(   1,  2, "2",   3,   1)
      );
array_multisort($ar[0], SORT_ASC, SORT_STRING,
                $ar[1], SORT_NUMERIC, SORT_DESC);
var_dump($ar);
?>

In this example, after sorting, the first array will transform to "10", 100, 100, 11, "a" (it was sorted as strings in ascending order). The second will contain 1, 3, "2", 2, 1 (sorted as numbers, in descending order).

array(2) {
  [0]=> array(5) {
    [0]=> string(2) "10"
    [1]=> int(100)
    [2]=> int(100)
    [3]=> int(11)
    [4]=> string(1) "a"
  }
  [1]=> array(5) {
    [0]=> int(1)
    [1]=> int(3)
    [2]=> string(1) "2"
    [3]=> int(2)
    [4]=> int(1)
  }
}

Voorbeeld: Sorting database results

 For this example, each element in the 
 array represents one row in a table. This type of dataset is typical
 of database records.
`data`

Example data:

volume | edition
-------+--------
    67 |       2
    86 |       1
    85 |       6
    98 |       2
    86 |       6
    67 |       7

 The data as an array, called . This would usually,
 for example, be obtained by looping with .
`data``mysqli_fetch_assoc`


 In this example, we will order by  descending,
  ascending.
`volume``edition`


 We have an array of rows, but 
 requires an array of columns, so we use the below code to obtain the
 columns, then perform the sorting.
`array_multisort`

<?php
// The data as created by looping over mysqli_fetch_assoc:
$data[] = array('volume' => 67, 'edition' => 2);
$data[] = array('volume' => 86, 'edition' => 1);
$data[] = array('volume' => 85, 'edition' => 6);
$data[] = array('volume' => 98, 'edition' => 2);
$data[] = array('volume' => 86, 'edition' => 6);
$data[] = array('volume' => 67, 'edition' => 7);

// Obtain a list of columns
foreach ($data as $key => $row) {
    $volume[$key]  = $row['volume'];
    $edition[$key] = $row['edition'];
}

// You can use array_column() instead of the above code
$volume  = array_column($data, 'volume');
$edition = array_column($data, 'edition');

// Sort the data with volume descending, edition ascending
// Add $data as the last parameter, to sort by the common key
array_multisort($volume, SORT_DESC, $edition, SORT_ASC, $data);

// Loop over the data and output the sorted values for each column
echo 'volume | edition', PHP_EOL;
echo '-------+--------', PHP_EOL;
for ($i = 0; $i < count($data); $i++) {
     printf("%6d | %7d\n", $volume[$i], $edition[$i]);
}
?>

The dataset is now sorted, and will look like this:

volume | edition
-------+--------
    98 |       2
    86 |       1
    86 |       6
    85 |       6
    67 |       2
    67 |       7

Voorbeeld: Case insensitive sorting

 Both  and
  are case sensitive, strings
 starting with a capital letter will come before strings starting
 with a lowercase letter.
`SORT_STRING``SORT_REGULAR`

To perform a case insensitive sort, force the sorting order to be determined by a lowercase copy of the original array.

<?php
$array = array('Alpha', 'atomic', 'Beta', 'bank');
$array_lowercase = array_map('strtolower', $array);

array_multisort($array_lowercase, SORT_ASC, SORT_STRING, $array);

print_r($array);
?>

Array
(
    [0] => Alpha
    [1] => atomic
    [2] => bank
    [3] => Beta
)

usort

Vorige ← array_merge Volgende array_pad →

array_multisort

array_multisort

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