array_multisort

(PHP 4, PHP 5, PHP 7, PHP 8)

array_multisort — 对多个数组或多维数组进行排序

说明

array_multisort(
    array &$array1,
    mixed $array1_sort_order = SORT_ASC,
    mixed $array1_sort_flags = SORT_REGULAR,
    mixed ...$rest
): bool

array_multisort() 可以用来一次对多个数组进行排序，或者根据某一维或多维对多维数组进行排序。

关联（string）键名保持不变，但数字键名会被重新索引。

注意:
如果两个成员完全相同，那么它们将保持原来的顺序。在 PHP 8.0.0 之前，它们在排序数组中的相对顺序是未定义的。

参数

注意:
重置数组中的内部指针，指向第一个元素。

array1

要排序的 array。

array1_sort_order

之前 array 参数要排列的顺序。 SORT_ASC 按照上升顺序排序， SORT_DESC 按照下降顺序排序。

此参数可以和 array1_sort_flags 互换，也可以完全删除，默认是 SORT_ASC 。

array1_sort_flags

为 array 参数设定选项：

排序类型标志：

SORT_REGULAR - 将项目按照通常方法比较（不修改类型）
SORT_NUMERIC - 按照数字大小比较
SORT_STRING - 按照字符串比较
SORT_LOCALE_STRING - 根据当前的本地化设置，按照字符串比较。它会使用 locale 信息，可以通过 setlocale() 修改此信息。
SORT_NATURAL - 以字符串的"自然排序"，类似 natsort()
SORT_FLAG_CASE - 可以组合 (按位或 OR) SORT_STRING 或者 SORT_NATURAL 大小写不敏感的方式排序字符串。

参数可以和 array1_sort_order 交换或者省略，默认情况下是 SORT_REGULAR。

rest

可选的选项，可提供更多数组，跟随在 sort order 和 sort flag 之后。提供的数组和之前的数组要有相同数量的元素。换言之，排序是按字典顺序排列的。

返回值

成功时返回 true，或者在失败时返回 false。

示例

示例 #1 多个数组排序

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

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

这个例子里，排序后，第一个数组会包含 0、 10、 100、 100。第二个数组会包含 4、1、 2、 3。第二个数组里的项目对应第一个数组后也进行了排序（100 和 100）。

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)
}

示例 #2 排序多维数组

<?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);
?>

本例中在排序后，第一个数组将变成 "10"，100，100，11，"a"（被当作字符串以升序排列）。第二个数组将包含 1, 3, "2", 2, 1（被当作数字以降序排列）。

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)
  }
}

示例 #3 对数据库结果进行排序

本例中 data 数组中的每个单元表示一个表中的一行。这是典型的数据库记录的数据集合。

例子中的数据如下：

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

数据全都存放在名为 data 的数组中。这通常是通过循环从数据库取得的结果，例如 mysql_fetch_assoc()。

<?php
$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);
?>

本例中将把 volume 降序排列，把 edition 升序排列。

现在有了包含有行的数组，但是 array_multisort() 需要一个包含列的数组，因此用以下代码来取得列，然后排序。

<?php
// 取得列的列表
foreach ($data as $key => $row) {
    $volume[$key]  = $row['volume'];
    $edition[$key] = $row['edition'];
}

// 你可以使用 array_column() 代替上面的代码
$volume  = array_column($data, 'volume');
$edition = array_column($data, 'edition');

// 将数据根据 volume 降序排列，根据 edition 升序排列
// 把 $data 作为最后一个参数，以通用键排序
array_multisort($volume, SORT_DESC, $edition, SORT_ASC, $data);
?>

数据集合现在排好序了，结果如下：

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

示例 #4 不区分大小写字母排序

SORT_STRING 和 SORT_REGULAR 都是区分大小写字母的，大写字母会排在小写字母之前。

要进行不区分大小写的排序，就要按照原数组的小写字母拷贝来排序。

<?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);
?>

以上示例会输出：

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

参见

usort() - 使用用户自定义的比较函数对数组中的值进行排序
数组排序函数对比

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用户贡献的备注 7 notes

down

225

jimpoz at jimpoz dot com ¶

14 years ago

I came up with an easy way to sort database-style results. This does what example 3 does, except it takes care of creating those intermediate arrays for you before passing control on to array_multisort(). 

<?php
function array_orderby()
{
    $args = func_get_args();
    $data = array_shift($args);
    foreach ($args as $n => $field) {
        if (is_string($field)) {
            $tmp = array();
            foreach ($data as $key => $row)
                $tmp[$key] = $row[$field];
            $args[$n] = $tmp;
            }
    }
    $args[] = &$data;
    call_user_func_array('array_multisort', $args);
    return array_pop($args);
}
?>

The sorted array is now in the return value of the function instead of being passed by reference.

<?php
$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);

// Pass the array, followed by the column names and sort flags
$sorted = array_orderby($data, 'volume', SORT_DESC, 'edition', SORT_ASC);
?>

down

matt at bosc dot io ¶

9 years ago

One-liner function to sort multidimensionnal array by key, thank's to array_column

<?php

array_multisort (array_column($array, 'key'), SORT_DESC, $array);

?>

down

cagret at gmail dot com ¶

15 years ago

A more inuitive way of sorting multidimensional arrays using array_msort() in just one line, you don't have to divide the original array into per-column-arrays:

<?php

$arr1 = array(
    array('id'=>1,'name'=>'aA','cat'=>'cc'),
    array('id'=>2,'name'=>'aa','cat'=>'dd'),
    array('id'=>3,'name'=>'bb','cat'=>'cc'),
    array('id'=>4,'name'=>'bb','cat'=>'dd')
);

$arr2 = array_msort($arr1, array('name'=>SORT_DESC, 'cat'=>SORT_ASC));

debug($arr1, $arr2);

arr1:
    0:
        id: 1 (int)
        name: aA (string:2)
        cat: cc (string:2)
    1:
        id: 2 (int)
        name: aa (string:2)
        cat: dd (string:2)
    2:
        id: 3 (int)
        name: bb (string:2)
        cat: cc (string:2)
    3:
        id: 4 (int)
        name: bb (string:2)
        cat: dd (string:2)
arr2:
    2:
        id: 3 (int)
        name: bb (string:2)
        cat: cc (string:2)
    3:
        id: 4 (int)
        name: bb (string:2)
        cat: dd (string:2)
    0:
        id: 1 (int)
        name: aA (string:2)
        cat: cc (string:2)
    1:
        id: 2 (int)
        name: aa (string:2)
        cat: dd (string:2)

function array_msort($array, $cols)
{
    $colarr = array();
    foreach ($cols as $col => $order) {
        $colarr[$col] = array();
        foreach ($array as $k => $row) { $colarr[$col]['_'.$k] = strtolower($row[$col]); }
    }
    $eval = 'array_multisort(';
    foreach ($cols as $col => $order) {
        $eval .= '$colarr[\''.$col.'\'],'.$order.',';
    }
    $eval = substr($eval,0,-1).');';
    eval($eval);
    $ret = array();
    foreach ($colarr as $col => $arr) {
        foreach ($arr as $k => $v) {
            $k = substr($k,1);
            if (!isset($ret[$k])) $ret[$k] = $array[$k];
            $ret[$k][$col] = $array[$k][$col];
        }
    }
    return $ret;

}

?>

down

Robert C ¶

11 years ago

Hi,

I would like to see the next code snippet to be added to http://nl3.php.net/array_multisort

Purpose: Sort a 2-dimensional array on some key(s)

Advantage of function: 
- uses PHP's array_multisort function for sorting;
- it prepares the arrays (needed by array_multisort) for you;
- allows the sort criteria be passed as a separate array (It is possible to use sort order and flags.); 
- easy to set/overwrite the way strings are sorted (case insensitive instead of case sensitive, which is PHP's default way of sorting);
- performs excellent 

function MultiSort($data, $sortCriteria, $caseInSensitive = true)
{
  if( !is_array($data) || !is_array($sortCriteria))
    return false;       
  $args = array(); 
  $i = 0;
  foreach($sortCriteria as $sortColumn => $sortAttributes)  
  {
    $colList = array(); 
    foreach ($data as $key => $row)
    { 
      $convertToLower = $caseInSensitive && (in_array(SORT_STRING, $sortAttributes) || in_array(SORT_REGULAR, $sortAttributes)); 
      $rowData = $convertToLower ? strtolower($row[$sortColumn]) : $row[$sortColumn]; 
      $colLists[$sortColumn][$key] = $rowData;
    }
    $args[] = &$colLists[$sortColumn];
      
    foreach($sortAttributes as $sortAttribute)
    {      
      $tmp[$i] = $sortAttribute;
      $args[] = &$tmp[$i];
      $i++;      
     }
  }
  $args[] = &$data;
  call_user_func_array('array_multisort', $args);
  return end($args);
} 

Usage:

//Fill an array with random test data
define('MAX_ITEMS', 15);
define('MAX_VAL', 20);
for($i=0; $i < MAX_ITEMS; $i++)
  $data[] = array('field1' => rand(1, MAX_VAL), 'field2' => rand(1, MAX_VAL), 'field3' => rand(1, MAX_VAL) );
  
//Set the sort criteria (add as many fields as you want)
$sortCriteria = 
  array('field1' => array(SORT_DESC, SORT_NUMERIC), 
       'field3' => array(SORT_DESC, SORT_NUMERIC)
  );

//Call it like this:  
$sortedData = MultiSort($data, $sortCriteria, true);

down

nick ([AT]) nickyost ([DOT]) com ¶

13 years ago

USort function can be used to sort multidimensional arrays with almost no work whatsoever by using the individual values within the custom sort function.

This function passes the entire child element even if it is not a string. If it is an array, as would be the case in multidimensional arrays, it will pass the whole child array as one parameter.

Therefore, do something elegant like this:

<?php
     // Sort the multidimensional array
     usort($results, "custom_sort");
     // Define the custom sort function
     function custom_sort($a,$b) {
          return $a['some_sub_var']>$b['some_sub_var'];
     }
?>

This does in 4 lines what other functions took 40 to 50 lines to do. This does not require you to create temporary arrays or anything. This is, for me, a highly preferred solution over this function.

Hope it helps!

down

Magento-User ¶

11 years ago

When sorting an array of (complex) objects, this function can give you a "Fatal error:  Nesting level too deep" since it directly compares elements in later arrays if the elements in earlier ones compare equal. This can be worked around with the Flag-Parameter:
<?php 
$sortKeys = array_map($extractKey, $lotsOfComplexObjects);
array_multisort($sortKeys, $lotsOfComplexObjects, SORT_ASC, SORT_NUMERIC);
?>
I'm replacing an 'uasort()'-call which is significantly slower since it leads to a lot of calls to the comparison-function but most of the objects involved are recursive.

If this 'trick' gives a wrong order,  you need a better key.

down

brettz9 throu gh yah ¶

18 years ago

Often, one may have a group of arrays which have parallel data that need to be kept associated with each other (e.g., the various attribute values of a group of elements might be stored in their own arrays). Using array_multisort as is, by specifying additional fields, it is possible, as in the documentation example cited below, that this association will be lost. 

To take this example set of data from the documentation:
<?php
$ar1 = array("10", 100, 100, "a");
$ar2 = array(1, 3, "2", 1);
?>

The example goes on to sort it this way:
<?php
array_multisort($ar1, $ar2);
?>

In this case, although the "10" remains associated with the first '1' after being sorted, the "2" and '3' are reversed from their original order.

In order to sort by one field only (yet still have the other array(s) being correspondingly sorted), one can use array_keys (which makes an array out of the keys) to ensure that no further sub-sorting is performed. This works because array_keys is making an array for which no duplicates can exist (since keys will be unique), and thus, the subsequent fields will have no relevance as far as subsorting.

So, using the above data, we can perform this sort instead:
<?php
$ar3 = array_keys($ar1);
array_multisort($ar1, $ar3, $ar2);
?>

which, when $ar1 and $ar2 are dumped gives:

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