PHP 5.4.33 Released

ksort

(PHP 4, PHP 5)

ksortOrdena um array pelas chaves

Descrição

int ksort ( array &$array [, int $sort_flags ] )

Ordena um array pelas chaves, mantendo a correlação entre as chaves e os valores. Essa função é bastante útil principalmente para arrays associativos.

Parâmetros

array

O array de entrada.

sort_flags

Você pode modificar o comportamento da ordenação através do parâmetro opcional sort_flags, para mais detalhes veja sort().

Valor Retornado

Retorna TRUE em caso de sucesso ou FALSE em caso de falha.

Changelog

Versão Descrição
4.0.0 O parâmetro opcional sort_flags foi adicionado.

Exemplos

Exemplo #1 Exemplo da ksort()

<?php
$frutas 
= array("d"=>"limao""a"=>"laranja""b" =>"banana""c"=>"maçã");
ksort($frutas);
foreach (
$fruits as $key => $val) {
    echo 
"$chave = $valor\n";
}
?>

O exemplo acima irá imprimir:

a = laranja
b = banana
c = maçã
d = limao

Veja Também

  • asort() - Ordena um array mantendo a associação entre índices e valores
  • arsort() - Ordena um array em ordem descrescente mantendo a associação entre índices e valores
  • krsort() - Ordena um array pelas chaves em ordem descrescente
  • uksort() - Ordena um array pelas chaves utilizando uma função de comparação definida pelo usuário.
  • sort() - Ordena um array
  • natsort() - Ordena um array utilizando o algoritmo da "ordem natural"
  • rsort() - Ordena um array em ordem descrescente

add a note add a note

User Contributed Notes 15 notes

up
9
DavidG
4 years ago
A nice way to do sorting of a key on a multi-dimensional array without having to know what keys you have in the array first:

<?php
$people
= array(
array(
"name"=>"Bob","age"=>8,"colour"=>"red"),
array(
"name"=>"Greg","age"=>12,"colour"=>"blue"),
array(
"name"=>"Andy","age"=>5,"colour"=>"purple"));

var_dump($people);

$sortArray = array();

foreach(
$people as $person){
    foreach(
$person as $key=>$value){
        if(!isset(
$sortArray[$key])){
           
$sortArray[$key] = array();
        }
       
$sortArray[$key][] = $value;
    }
}

$orderby = "name"; //change this to whatever key you want from the array

array_multisort($sortArray[$orderby],SORT_DESC,$people);

var_dump($people);
?>

Output from first var_dump:

[0]=&gt;
  array(3) {
    ["name"]=&gt;
    string(3) "Bob"
    ["age"]=&gt;
    int(8)
    ["colour"]=&gt;
    string(3) "red"
  }
  [1]=&gt;
  array(3) {
    ["name"]=&gt;

    string(4) "Greg"
    ["age"]=&gt;
    int(12)
    ["colour"]=&gt;
    string(4) "blue"
  }
  [2]=&gt;
  array(3) {
    ["name"]=&gt;
    string(4) "Andy"
    ["age"]=&gt;
    int(5)
    ["colour"]=&gt;

    string(6) "purple"
  }
}

Output from 2nd var_dump:

array(3) {
  [0]=&gt;
  array(3) {
    ["name"]=&gt;
    string(4) "Greg"
    ["age"]=&gt;
    int(12)
    ["colour"]=&gt;
    string(4) "blue"
  }
  [1]=&gt;
  array(3) {
    ["name"]=&gt;

    string(3) "Bob"
    ["age"]=&gt;
    int(8)
    ["colour"]=&gt;
    string(3) "red"
  }
  [2]=&gt;
  array(3) {
    ["name"]=&gt;
    string(4) "Andy"
    ["age"]=&gt;
    int(5)
    ["colour"]=&gt;

    string(6) "purple"
  }

There's no checking on whether your array keys exist, or the array data you are searching on is actually there, but easy enough to add.
up
3
Anonymous
1 year ago
Note that this function will output the given $fields in the order they were added to the data array and not automatically in numerical key order.

To output in ascending key order, you'll need to ksort the array first (or use appropriate natural order sorting, depending on your keys).

For example:
<?php
$data
[2] = 'C';
$data[0] = 'A';
$data[1] = 'B';

fputcsv($fh, $data); // outputs: "C,A,B"

ksort($data);
fputcsv($fh, $data); // outputs: "A,B,C"
?>
up
3
Anonymous
12 years ago
here 2 functions to ksort/uksort an array and all its member arrays

function tksort(&$array)
  {
  ksort($array);
  foreach(array_keys($array) as $k)
    {
    if(gettype($array[$k])=="array")
      {
      tksort($array[$k]);
      }
    }
  }

function utksort(&$array, $function)
  {
  uksort($array, $function);
  foreach(array_keys($array) as $k)
    {
    if(gettype($array[$k])=="array")
      {
      utksort($array[$k], $function);
      }
    }
  }
up
3
thegrandoverseer
2 years ago
I wrote this function to sort the keys of an array using an array of keynames, in order.
<?php
/**
* function array_reorder_keys
* reorder the keys of an array in order of specified keynames; all other nodes not in $keynames will come after last $keyname, in normal array order
* @param array &$array - the array to reorder
* @param mixed $keynames - a csv or array of keynames, in the order that keys should be reordered
*/
function array_reorder_keys(&$array, $keynames){
    if(empty(
$array) || !is_array($array) || empty($keynames)) return;
    if(!
is_array($keynames)) $keynames = explode(',',$keynames);
    if(!empty(
$keynames)) $keynames = array_reverse($keynames);
    foreach(
$keynames as $n){
        if(
array_key_exists($n, $array)){
           
$newarray = array($n=>$array[$n]); //copy the node before unsetting
           
unset($array[$n]); //remove the node
           
$array = $newarray + array_filter($array); //combine copy with filtered array
       
}
    }
}
$seed_array = array('foo'=>'bar', 'someotherkey'=>'whatev', 'bar'=>'baz', 'baz'=>'foo', 'anotherkey'=>'anotherval');
array_reorder_keys($seed_array, 'baz,foo,bar'); //returns array('baz'=>'foo', 'foo'=>'bar', 'bar'=>'baz', 'someotherkey'=>'whatev', 'anotherkey'=>'anotherval' );
?>
up
2
Anonymous
7 months ago
@thegrandoverseer 

you could also use the build-in php array functions to get exactly what you want to have:

<?php
        $seed_array
= array('foo'=>'bar', 'someotherkey'=>'whatev', 'bar'=>'baz', 'baz'=>'foo', 'anotherkey'=>'anotherval');
       
$keys_array = array('baz', 'foo', 'bar');

       
$return_array = array_intersect_key($seed_array, array_flip($keys_array)) + array_diff_key($seed_array, array_flip($keys_array));

?>
up
2
ssb45 at cornell dot edu
9 years ago
The function that justin at booleangate dot org provides works well, but be aware that it is not a drop-in replacement for ksort as is.  While ksort sorts the array by reference and returns a status boolean, natksort returns the sorted array, leaving the original untouched.  Thus, you must use this syntax:

$array = natksort($array);

If you want to use the more natural syntax:

$status = natksort($array);

Then use this modified version:

function natksort(&$array) {
    $keys = array_keys($array);
    natcasesort($keys);

    foreach ($keys as $k) {
        $new_array[$k] = $array[$k];
    }

    $array = $new_array;
    return true;
}
up
2
delvach at mail dot com
12 years ago
A real quick way to do a case-insensitive sort of an array keyed by strings:

uksort($myArray, "strnatcasecmp");
up
1
serpro at gmail dot com
5 years ago
Here is a function to sort an array by the key of his sub-array.

<?php

function sksort(&$array, $subkey="id", $sort_ascending=false) {

    if (
count($array))
       
$temp_array[key($array)] = array_shift($array);

    foreach(
$array as $key => $val){
       
$offset = 0;
       
$found = false;
        foreach(
$temp_array as $tmp_key => $tmp_val)
        {
            if(!
$found and strtolower($val[$subkey]) > strtolower($tmp_val[$subkey]))
            {
               
$temp_array = array_merge(    (array)array_slice($temp_array,0,$offset),
                                            array(
$key => $val),
                                           
array_slice($temp_array,$offset)
                                          );
               
$found = true;
            }
           
$offset++;
        }
        if(!
$found) $temp_array = array_merge($temp_array, array($key => $val));
    }

    if (
$sort_ascending) $array = array_reverse($temp_array);

    else
$array = $temp_array;
}

?>

Example
<?php
$info
= array("peter" => array("age" => 21,
                                          
"gender" => "male"
                                          
),
                  
"john"  => array("age" => 19,
                                          
"gender" => "male"
                                          
),
                  
"mary" => array("age" => 20,
                                          
"gender" => "female"
                                         
)
                  );

sksort($info, "age");
var_dump($info);

sksort($info, "age", true);
var_dump($ifno);
?>

This will be the output of the example:

/*DESCENDING SORT*/
array(3) {
  ["peter"]=>
  array(2) {
    ["age"]=>
    int(21)
    ["gender"]=>
    string(4) "male"
  }
  ["mary"]=>
  array(2) {
    ["age"]=>
    int(20)
    ["gender"]=>
    string(6) "female"
  }
  ["john"]=>
  array(2) {
    ["age"]=>
    int(19)
    ["gender"]=>
    string(4) "male"
  }
}

/*ASCENDING SORT*/
array(3) {
  ["john"]=>
  array(2) {
    ["age"]=>
    int(19)
    ["gender"]=>
    string(4) "male"
  }
  ["mary"]=>
  array(2) {
    ["age"]=>
    int(20)
    ["gender"]=>
    string(6) "female"
  }
  ["peter"]=>
  array(2) {
    ["age"]=>
    int(21)
    ["gender"]=>
    string(4) "male"
  }
}
up
1
justin at booleangate dot org
9 years ago
Here's a handy function for natural order sorting on keys.

function natksort($array) {
  // Like ksort but uses natural sort instead
  $keys = array_keys($array);
  natsort($keys);

  foreach ($keys as $k)
    $new_array[$k] = $array[$k];

  return $new_array;
}
up
1
stephen [ at ] brooksie-net [ dot ] co [ dot ] uk
1 year ago
ksort and krsort fail to undestand scientific notation, https://bugs.php.net/bug.php?id=43053, therefore when sorting numeric keys, if the key is of the form 0.00001 php will represent it as 1.0E-5.

These methods will assume this to be a string and therefore not organise your array as you may expect.

When using value of this form for array keys use sprintf('%f', 0.00001) to generate the key, for smaller values the precision needs to be included
e.g. sprintf('%0.10f', 0.00000001)
up
0
bimal at sanjaal dot com
3 months ago
An example of reverse sorting a domain name by its name.

<?php
$domains
= array(
   
'sub.domain.com',
   
'sub2.domain.com',
);

foreach(
$domains as $d => $domain)
{
   
$chunks = explode('.', $domain);
   
krsort($chunks);

    echo
"\r\n<br>", implode('/', $chunks);
}

/**
* Outputs as:
*
* com/domain/sub
* com/domain/sub2
*/
?>
up
0
centraleffects at yahoo dot com
1 year ago
I wrote this function to sort meta_value in wordpress. I tried a lot of array sorting but neither of them work. But this is not suitable for multidimensional array. This is intended only for wordpress meta_value

The problem is to sort below( the order should be ascending; alphabetically then numerically like A-Z then 0-9):
500-999 users
25-49 users
All Sizes
1-4 users
5-9 users
10-24 users
250-499 users
1000-4999
5000-9999

The solution:

function array_sort($arr){
    if(is_array($arr)){
        $numeric = array();
        $string = array();
        foreach($arr as $k => $v)
        {
            if(isset($v["meta_value"])){
                 $str = explode(" ",trim($v["meta_value"]));
                 $firstWord  = explode("-",trim($str[0]));
             }else{
                 $str = $v;
                 $firstWord  = explode("-",trim($str));
             }

            $firstWord = $firstWord[0];

            if(is_numeric($firstWord))
            {
                $numeric[(int)$firstWord] = $v;
            }else{
                $string[$firstWord] = $v;
            }
            unset($firstWord);
        }
        ksort($string,SORT_STRING);
        ksort($numeric,SORT_NUMERIC);

        return array_merge((array)$string, (array)$numeric);
    }
   

    return false;
}

The usage:
$meta =get_post_meta($post_id,$meta_key);
$sorted = array_sort($meta);

The result:
All Sizes
1-4 users
5-9 users
10-24 users
25-49 users
250-499 users
500-999 users
1000-4999
5000-9999
up
0
sbarnum at mac dot com
12 years ago
ksort on an array with negative integers as keys yields some odd results.  Not sure if this is a bad idea (negative key values) or what.
up
-1
jakub dot lopuszanski at nasza-klasa dot pl
3 years ago
Note that ksort will NOT help you much if numeric and string keys are mixed together.
<?php
$t
= array(
 
"a"=>"A",
 
0=>"A",
 
"b"=>"A",
 
1=>"A"
);
var_dump($t);
ksort($t);
var_dump($t);
?>

produces (on PHP 5.3.6-4 with Suhosin-Patch) :

array(4) {
  ["a"]=>
  string(1) "A"
  [0]=>
  string(1) "A"
  ["b"]=>
  string(1) "A"
  [1]=>
  string(1) "A"
}

array(4) {
  ["b"]=>
  string(1) "A"
  [0]=>
  string(1) "A"
  ["a"]=>
  string(1) "A"
  [1]=>
  string(1) "A"
}

note that the second array should be sorted by keys, but is even more messed up than the first one!
up
-2
maik dot riechert at animey dot net
6 years ago
Be careful when using ksort for mixed type keys!!

$a = array(
    'first' => true,
    0       => 'sally',
);

$b = array(
    0       => 'sally',
    'first' => true,
);

ksort($a);
ksort($b);
var_dump($a);
var_dump($b);

Output is:
array(
    0 => 'sally',
    'first' => true,
)

array(
    'first' => true,
    0 => 'sally',
)

If you want same results for both arrays, use:

ksort($a, SORT_STRING);

The reason for that lays in the compare mechanism which would normally just typecast 'first' to an integer or 0 to a string when comparing it to each other. So you have to use SORT_STRING, otherwise you would lose information when 'first' is converted to int.
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