sort

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

sort — Sort an array in ascending order

Description

sort(array &$array, int $flags = SORT_REGULAR): true

Sorts array in place by values in ascending order.

Note:
If two members compare as equal, they retain their original order. Prior to PHP 8.0.0, their relative order in the sorted array was undefined.

Note: This function assigns new keys to the elements in array. It will remove any existing keys that may have been assigned, rather than just reordering the keys.

Note:
Resets array's internal pointer to the first element.

Parameters

array

The input array.

flags

The optional second parameter flags may be used to modify the sorting behavior using these values:

Sorting type flags:

SORT_REGULAR - compare items normally; the details are described in the comparison operators section
SORT_NUMERIC - compare items numerically
SORT_STRING - compare items as strings
SORT_LOCALE_STRING - compare items as strings, based on the current locale. It uses the locale, which can be changed using setlocale()
SORT_NATURAL - compare items as strings using "natural ordering" like natsort()
SORT_FLAG_CASE - can be combined (bitwise OR) with SORT_STRING or SORT_NATURAL to sort strings case-insensitively

Return Values

Always returns true.

Changelog

Version	Description
8.2.0	The return type is `true` now; previously, it was bool.

Examples

Example #1 sort() example

<?php

$fruits = array("lemon", "orange", "banana", "apple");
sort($fruits);
foreach ($fruits as $key => $val) {
    echo "fruits[" . $key . "] = " . $val . "\n";
}

?>

The above example will output:

fruits[0] = apple
fruits[1] = banana
fruits[2] = lemon
fruits[3] = orange

The fruits have been sorted in alphabetical order.

Example #2 sort() example using case-insensitive natural ordering

<?php

$fruits = array(
    "Orange1", "orange2", "Orange3", "orange20"
);
sort($fruits, SORT_NATURAL | SORT_FLAG_CASE);
foreach ($fruits as $key => $val) {
    echo "fruits[" . $key . "] = " . $val . "\n";
}

?>

The above example will output:

fruits[0] = Orange1
fruits[1] = orange2
fruits[2] = Orange3
fruits[3] = orange20

The fruits have been sorted like natcasesort().

Notes

Note: Like most PHP sorting functions, sort() uses an implementation of » Quicksort. The pivot is chosen in the middle of the partition resulting in an optimal time for already sorted arrays. This is however an implementation detail you shouldn't rely on.

Warning

Be careful when sorting arrays with mixed types values because sort() can produce unexpected results, if flags is SORT_REGULAR.

Found A Problem?

Learn How To Improve This Page • Submit a Pull Request • Report a Bug

＋add a note

User Contributed Notes 35 notes

down

221

phpdotnet at m4tt dot co dot uk ¶

14 years ago

down

Md. Abutaleb ¶

4 years ago

<?php 
/*
As I found the sort() function normally works as ascending order based on the following priority :
1. NULL
2. Empty 
3. Boolean FALSE 
4. String 
5. Float 
6. Int 
7. Array
8. Object 

Consider the following array: 
*/

$a = ['fruit'=> 'apple', 'A' => 10, 20, 5, 2.5, 5=>'A new value', 'last' => 'value', TRUE, NULL, "", FALSE, array(), new StdClass];
sort($a);
var_dump($a);

#The output is: 

array(13) {
  [0]=>NULL
  [1]=> string(0) ""
  [2]=>bool(false)
  [3]=>string(11) "A new value"
  [4]=>string(5) "apple"
  [5]=>string(5) "value"
  [6]=> float(2.5)
  [7]=> int(5)
  [8]=>int(10)
  [9]=>int(20)
  [10]=>array(0) { }
  [11]=> bool(true)
  [12]=>object(stdClass)#1 (0) {}
}

//Hope it will remove your confusion when you're sorting an array with mix type data. 
?>

down

aminkhoshzahmat at gmail dot com ¶

4 years ago

Let's say we have a list of names, and it is not sorted.

<?php

$names = array('Amin', 'amir', 'sarah', 'Somayeh', 'armita', 'Armin');

sort($names); // simple alphabetical sort
print_r($names);
?>
Result is :
Array
(
    [0] => Amin
    [1] => Armin
    [2] => Somayeh // actually it's not sort alphabetically from here!
    [3] => amir         // comparison is based on ASCII values.
    [4] => armita
    [5] => sarah
)

If you want to sort alphabeticaly no matter it is upper or lower case:

<?php

sort($names, SORT_STRING | SORT_FLAG_CASE);
print_r($names);
?>

Result is:
Array
(
    [0] => Amin
    [1] => amir
    [2] => Armin
    [3] => armita
    [4] => sarah
    [5] => Somayeh
)

down

Walter Tross ¶

13 years ago

unless you specify the second argument, "regular" comparisons will be used. I quote from the page on comparison operators:
"If you compare a number with a string or the comparison involves numerical strings, then each string is converted to a number and the comparison performed numerically."
What this means is that "10" < "1a", and "1a" < "2", but "10" > "2". In other words, regular PHP string comparisons are not transitive.
This implies that the output of sort() can in rare cases depend on the order of the input array:
<?php
function echo_sorted($a)
{
   echo "{$a[0]} {$a[1]} {$a[2]}";
   sort($a);
   echo " => {$a[0]} {$a[1]} {$a[2]}\n";
}
// on PHP 5.2.6:
echo_sorted(array( "10", "1a", "2")); // => 10 1a 2
echo_sorted(array( "10", "2", "1a")); // => 1a 2 10
echo_sorted(array( "1a", "10", "2")); // => 2 10 1a
echo_sorted(array( "1a", "2", "10")); // => 1a 2 10
echo_sorted(array( "2", "10", "1a")); // => 2 10 1a
echo_sorted(array( "2", "1a", "10")); // => 10 1a 2
?>

down

Abhishek Banerjee ¶

8 years ago

down

eriewave at hotmail dot com ¶

14 years ago

If you need to sort an array containing some equivalent values and you want the equivalents to end up next to each other in the overall order (similar to a MySQL's ORDER BY output), rather than breaking the function, do this:

<?php

sort($array, ksort($array))

?>

-When the sort() function finds two equivalents, it will sort them arbitrarily by their key #'s as a second parameter.

-Dirk

down

danm68 at gmail dot com ¶

15 years ago

sort() used with strings doesn't sort just alphabetically. It sorts all upper-case strings alphabetically first and then sorts lower-case strings alphabetically second. 
Just in case anyone was as confused as I was and I've never seen this mentioned anywhere.

down

ajanata at gmail dot com ¶

13 years ago

This took me longer than it should have to figure out, but if you want the behavior of sort($array, SORT_STRING) (that is, re-indexing the array unlike natcasesort) in a case-insensitive manner, it is a simple matter of doing usort($array, strcasecmp).

down

joris at mangrove dot nl ¶

17 years ago

Commenting on note http://www.php.net/manual/en/function.sort.php#62311 :

Sorting an array of objects will not always yield the results you desire.

As pointed out correctly in the note above, sort() sorts the array by value of the first member variable. However, you can not always assume the order of your member variables! You must take into account your class hierarchy!

By default, PHP places the inherited member variables on top, meaning your first member variable is NOT the first variable in your class definition! 
However, if you use code analyzers or a compile cache, things can be very different. E.g., in eAccelerator, the inherited member variables are at the end, meaning you get different sort results with caching on or off.

Conclusion:
Never use sort on arrays with values of a type other than scalar or array.

down

williamprogphp at[pleaseNOTSPAM] yahoo d ¶

11 years ago

In order to make some multidimensional quick sort implementation, take advantage of this stuff

<?php
        function quickSortMultiDimensional($array, $chave) {
            if( count( $array ) < 2 ) {
                return $array;
            }
            $left = $right = array( );
            reset( $array );
            $pivot_key    = key( $array );
            $pivot    = array_shift( $array );
            foreach( $array as $k => $v ) {
                if( $v[$chave] < $pivot[$chave] )
                        $left[$k][$chave] = $v[$chave];
                else
                        $right[$k][$chave] = $v[$chave];
            }
            return array_merge(
                                    quickSortMultiDimensional($left, $chave), 
                                    array($pivot_key => $pivot), 
                                    quickSortMultiDimensional($right, $chave)
            );            
        }
?>

I make it using the idea from pageconfig dot com

tks for viewing

down

matpatnik at hotmail dot com ¶

16 years ago

This function will sort entity letters eg:&eacute;

I hope that help someone

function sort_entity($array) {
    $total = count($array);
    for ($i=0;$i<$total;$i++) {
        if ($array[$i]{0} == '&') {
            $array[$i] = $array[$i]{1}.$array[$i];
        } else {
            $array[$i] = $array[$i]{0}.$array[$i];
        }
    }
    sort($array);
    
    for ($i=0;$i<$total;$i++) {
        $array[$i] = substr($array[$i],1);
    }
    
    return $array;
}

down

peek at mailandnews dot com ¶

23 years ago

I ran into the same problem with case insensitive sorting. Actually I think there should be a SORT_STRING_CASE flag but I tried the following:



usort($listing, 'strcasecmp');



This didn't work (why not?), but you can do a proper case insensitive sort like this:



usort($listing, create_function('$a,$b','return strcasecmp($a,$b);'));

down

r at rcse dot de ¶

6 years ago

Here is no word about sorting UTF-8 strings by any collation. This should not be so uncommon?

down

stepmuel at ee dot ethz dot ch ¶

16 years ago

A little shorter way to sort an array of objects; with a callback function.

<?php 
function objSort(&$objArray,$indexFunction,$sort_flags=0) {
    $indices = array();
    foreach($objArray as $obj) {
        $indeces[] = $indexFunction($obj);
    }
    return array_multisort($indeces,$objArray,$sort_flags);
}

function getIndex($obj) {
    return $obj->getPosition();
}

objSort($objArray,'getIndex'); 
?>

down

aditycse at gmail dot com ¶

9 years ago

/*
 * Name : Aditya Mehrotra 
 * Email: aditycse@gmail.com
 */
//Example for sorting by values for an alphanumeric array also having case-sensitive data
$exampleArray1 = $exampleArray2 = array(
    0 => 'example1',
    1 => 'Example10',
    2 => 'example12',
    3 => 'Example2',
    4 => 'example3',
    5 => 'EXAMPLE10',
    6 => 'example10'
);

//default sorting
asort($exampleArray1);

// alphanumeric with case-sensitive data sorting by values
asort($exampleArray2, SORT_STRING | SORT_FLAG_CASE | SORT_NATURAL);

//output of defaut sorting
print_r($exampleArray1);
/*
 * output of default sorting
  Array
  (
  [5] => EXAMPLE10
  [1] => Example10
  [3] => Example2
  [0] => example1
  [6] => example10
  [2] => example12
  [4] => example3
  )
 */

print_r($exampleArray2);
/*
 * output of alphanumeric with case-sensitive data sorting by values
 Array
(
    [0] => example1
    [3] => Example2
    [4] => example3
    [5] => EXAMPLE10
    [1] => Example10
    [6] => example10
    [2] => example12
)
 */

down

me[ at ]szczepan[ dot ]info ¶

12 years ago

Sorting the keys, but keep the values in order is not possible by just ordering, because it would result in a new array. This is also the solution: Create a new array

<?php
$a = array(9=>"a",8=>"c",5=>"d");

$keys = array_keys($a);
sort($keys);
$result = array_combine($keys, array_values($a));

//Result : array(5=>"a",8=>"c",9=>"d");
?>

down

alex dot hristov dot 88 at gmail dot com ¶

13 years ago

As some people have mentioned before sorting a multidimentional array can be a bit tricky. it took me quite a while to get it going but it works as a charm:

<?php
//$order has to be either asc or desc
 function sortmulti ($array, $index, $order, $natsort=FALSE, $case_sensitive=FALSE) {
        if(is_array($array) && count($array)>0) {
            foreach(array_keys($array) as $key) 
            $temp[$key]=$array[$key][$index];
            if(!$natsort) {
                if ($order=='asc')
                    asort($temp);
                else    
                    arsort($temp);
            }
            else 
            {
                if ($case_sensitive===true)
                    natsort($temp);
                else
                    natcasesort($temp);
            if($order!='asc') 
                $temp=array_reverse($temp,TRUE);
            }
            foreach(array_keys($temp) as $key) 
                if (is_numeric($key))
                    $sorted[]=$array[$key];
                else    
                    $sorted[$key]=$array[$key];
            return $sorted;
        }
    return $sorted;
}
?>

down

cmarshall at gmx dot de ¶

13 years ago

I read up on various problems re: sort() and German Umlaut chars and my head was soon spinning - bug in sort() or not, solution via locale or not, etc. ... (a total newbie here).

The obvious solution for me was quick and dirty: transform the Umlaut chars (present as HTML codes in my case) to their normal equivalent ('ä' = 'ae', 'ö' = 'oe', 'ü' = 'ue', 'ß' = 'ss' etc.), sort the array, then transform back. However there are cases in which a 'Mueller' is really that and does NOT need to be transformed into 'Müller' afterwards. Hence I for example replace the Umlaut itself with it's normal equivalent plus a char not used in the string otherwise (e.g. '_') so that the transfer back to Umlaut would only take place on certain combinations.

Of course any other char instead of '_' can be used as additional char (influencing the sort result). I know that my solution is rough at the edges and may cause other sort problems but it was sufficient for my purpose.

The array '$dat' in this example was filled with German town names (I actually worked with a multiple array ('$dat[][]') but stripped the code down to this as it's easier to understand):

<?php
// START Pre-sorting (Umlaut -> normal letters)
$max = count($dat);
for($totcnt = 0; $totcnt < $max; $totcnt++){
   $dat[$totcnt]=str_replace('&szlig;','ss_',$dat[$totcnt]);
   $dat[$totcnt]=str_replace('&Auml;','Ae_',$dat[$totcnt]);
   $dat[$totcnt]=str_replace('&auml;','ae_',$dat[$totcnt]);
   $dat[$totcnt]=str_replace('&Ouml;','Oe_',$dat[$totcnt]);
   $dat[$totcnt]=str_replace('&ouml;','oe_',$dat[$totcnt]);
   $dat[$totcnt]=str_replace('&Uuml;','Ue_',$dat[$totcnt]);
   $dat[$totcnt]=str_replace('&uuml;','ue_',$dat[$totcnt]);
}
// END Pre-sorting (Umlaut -> normal letters)

// START Sorting //
function compare_towns($a, $b)
{
return strnatcmp($a, $b);
}
usort($dat, 'compare_towns');
// END Sorting //

// START Post-sorting (normal letters -> Umlaut)
for($totcnt = 0; $totcnt < $max; $totcnt++){
   $dat[$totcnt]=str_replace('ss_','&szlig;',$dat[$totcnt]);
   $dat[$totcnt]=str_replace('Ae_','&Auml;',$dat[$totcnt]);
   $dat[$totcnt]=str_replace('ae_','&auml;',$dat[$totcnt]);
   $dat[$totcnt]=str_replace('Oe_','&Ouml;',$dat[$totcnt]);
   $dat[$totcnt]=str_replace('oe_','&ouml;',$dat[$totcnt]);
   $dat[$totcnt]=str_replace('Ue_','&Uuml;',$dat[$totcnt]);
   $dat[$totcnt]=str_replace('ue_','&uuml;',$dat[$totcnt]);
}
// END Post-sorting (normal letters -> Umlaut)
?>

down

alishahnovin at hotmail dot com ¶

17 years ago

I had a multidimensional array, which needed to be sorted by one of the keys. This is what I came up with...

<?php
function msort($array, $id="id") {
        $temp_array = array();
        while(count($array)>0) {
            $lowest_id = 0;
            $index=0;
            foreach ($array as $item) {
                if ($item[$id]<$array[$lowest_id][$id]) {
                    $lowest_id = $index;
                }
                $index++;
            }
            $temp_array[] = $array[$lowest_id];
            $array = array_merge(array_slice($array, 0,$lowest_id), array_slice($array, $lowest_id+1));
        }
        return $temp_array;
    }
?>

Ex:

<?php

//oh no, this is not in the ordered by id!!
$data[] = array("item"=>"item 4", "id"=>4);
$data[] = array("item"=>"item 1", "id"=>1);
$data[] = array("item"=>"item 3", "id"=>3);
$data[] = array("item"=>"item 2", "id"=>2);

var_dump(  msort($data)  ); //just msort it!

/* outputs 

array
  0 => 
    array
      'item' => 'item 1' (length=6)
      'id' => 1
  1 => 
    array
      'item' => 'item 2' (length=6)
      'id' => 2
  2 => 
    array
      'item' => 'item 3' (length=6)
      'id' => 3
  3 => 
    array
      'item' => 'item 4' (length=6)
      'id' => 4

*/

?>

down

alex [at] vkpb [dot] com ¶

17 years ago

Sorting of an array by a method of inserts.

<?

  
       function sortByField($multArray,$sortField,$desc=true){
            $tmpKey='';
            $ResArray=array();

            $maIndex=array_keys($multArray);
            $maSize=count($multArray)-1;

            for($i=0; $i < $maSize ; $i++) {

               $minElement=$i;
               $tempMin=$multArray[$maIndex[$i]][$sortField];
               $tmpKey=$maIndex[$i];

                for($j=$i+1; $j <= $maSize; $j++)
                  if($multArray[$maIndex[$j]][$sortField] < $tempMin ) {
                     $minElement=$j;
                     $tmpKey=$maIndex[$j];
                     $tempMin=$multArray[$maIndex[$j]][$sortField];

                  }
                  $maIndex[$minElement]=$maIndex[$i];
                  $maIndex[$i]=$tmpKey;
            }

           if($desc)
               for($j=0;$j<=$maSize;$j++)
                  $ResArray[$maIndex[$j]]=$multArray[$maIndex[$j]];
           else
              for($j=$maSize;$j>=0;$j--)
                  $ResArray[$maIndex[$j]]=$multArray[$maIndex[$j]];

           return $ResArray;
       }

// make array
$array['aaa']=array("name"=>"vasia","order"=>1);
$array['bbb']=array("name"=>"petia","order"=>2);
$array['ccc']=array("name"=>"kolia","order"=>3);
$array['ddd']=array("name"=>"zenia","order"=>4);

// set sort 
$SortOrder=0; // desc by default , 1- asc

var_dump(sortByField($array,'order',$SortOrder));

array
  'ddd' => 
    array
      'name' => 'zenia' (length=5)
      'order' => 4
  'aaa' => 
    array
      'name' => 'vasia' (length=5)
      'order' => 1
  'bbb' => 
    array
      'name' => 'petia' (length=5)
      'order' => 2
  'ccc' => 
    array
      'name' => 'kolia' (length=5)
      'order' => 3

?>

down

Emiliyan at ServicesBG dot Com ¶

18 years ago

#This is a function that will sort an array...
function sort_by($array,  $keyname = null, $sortby) {
   $myarray = $inarray = array();    
   # First store the keyvalues in a seperate array
    foreach ($array as $i => $befree) { 
        $myarray[$i] = $array[$i][$keyname];
    }
   # Sort the new array by
    switch ($sortby) {
    case 'asc':
    # Sort an array and maintain index association...
    asort($myarray); 
    break;
    case 'arsort':
    # Sort an array in reverse order and maintain index association 
    arsort($myarray); 
    break;
    case 'natcasesor':
    # Sort an array using a case insensitive "natural order" algorithm
    natcasesort($myarray); 
    break;
    }
    # Rebuild the old array
    foreach ( $myarray as $key=> $befree) {
       $inarray[$key] = $array[$key];
    }
    return $inarray;
} 
sort_by(); example...
$info = sort_by($myarray, 'name', $use = 'asc');    
print_r($info);

down

nm at thenoodleman dot com ¶

18 years ago

Faster, more effective function:

array_sort (array, ['asc'/'desc'])

Second parameter specifies whether to order ascending or descending. Default is ascending.

function array_sort($array, $type='asc'){
    $result=array();
    foreach($array as $var => $val){
        $set=false;
        foreach($result as $var2 => $val2){
            if($set==false){
                if($val>$val2 && $type=='desc' || $val<$val2 && $type=='asc'){
                    $temp=array();
                    foreach($result as $var3 => $val3){
                        if($var3==$var2) $set=true;
                        if($set){
                            $temp[$var3]=$val3;
                            unset($result[$var3]);
                        }
                    }
                    $result[$var]=$val;    
                    foreach($temp as $var3 => $val3){
                        $result[$var3]=$val3;
                    }
                }
            }
        }
        if(!$set){
            $result[$var]=$val;
        }
    }
    return $result;
}

Works for ordering by integers or strings, no need to specify which.

Example:

$array=array('a' => 50, 'b' => 25, 'c' => 75);
print_r(array_sort($array));

Returns:
Array
(
[b] => 25
[a] => 50
[c] => 75
)

down

james at miicro dot net ¶

19 years ago

It's useful to know that if you're using this function on a multidimensional array, php will sort the first key, then the second and so on. This is similar to being able to use SQL to order by field1, field2 etc.

So:

Array ( 
[0] => Array ( [category] => work [name] => Smith ) 
[1] => Array ( [category] => play [name] => Johnson ) 
[2] => Array ( [category] => work [name] => Berger )
)

will become:

Array ( 
[0] => Array ( [category] => play [name] => Johnson )
[1] => Array ( [category] => work [name] => Berger ) 
[2] => Array ( [category] => work [name] => Smith ) 
)

Hope it helps someone.

down

timc at hlyw dot com ¶

19 years ago

I dig the multi_sort function(s) from above.  But, they don't work for hash arrays.  I added a keys variable to keep track of the key value as the array gets sorted.  Feed back welcome.

<?php
function array_qsort (&$array, $column=0, $order=SORT_ASC, $first=0, $last= -2) 
{ 
  // $array  - the array to be sorted 
  // $column - index (column) on which to sort 
  //          can be a string if using an associative array 
  // $order  - SORT_ASC (default) for ascending or SORT_DESC for descending 
  // $first  - start index (row) for partial array sort 
  // $last  - stop  index (row) for partial array sort 
  // $keys  - array of key values for hash array sort
  
  $keys = array_keys($array);
  if($last == -2) $last = count($array) - 1; 
  if($last > $first) { 
   $alpha = $first; 
   $omega = $last;
   $key_alpha = $keys[$alpha]; 
   $key_omega = $keys[$omega];
   $guess = $array[$key_alpha][$column]; 
   while($omega >= $alpha) { 
     if($order == SORT_ASC) { 
       while($array[$key_alpha][$column] < $guess) {$alpha++; $key_alpha = $keys[$alpha]; }
       while($array[$key_omega][$column] > $guess) {$omega--; $key_omega = $keys[$omega]; }
     } else { 
       while($array[$key_alpha][$column] > $guess) {$alpha++; $key_alpha = $keys[$alpha]; }
       while($array[$key_omega][$column] < $guess) {$omega--; $key_omega = $keys[$omega]; }
     } 
     if($alpha > $omega) break; 
     $temporary = $array[$key_alpha]; 
     $array[$key_alpha] = $array[$key_omega]; $alpha++;
     $key_alpha = $keys[$alpha];
     $array[$key_omega] = $temporary; $omega--;
     $key_omega = $keys[$omega];
   } 
   array_qsort ($array, $column, $order, $first, $omega); 
   array_qsort ($array, $column, $order, $alpha, $last); 
  } 
} 
?>

down

arjan321 at hotmail dot com ¶

21 years ago

Ik you want to sort case insensitive, use the natcasesort()

down

-1

petr dot biza at gmail dot com ¶

15 years ago

Here is a function to sort an array by the key of his sub-array with keep key in top level.



<?php

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

    $temp_array = $array;



    foreach ($temp_array as $key => &$value) {

      

      $sort = array();

      foreach ($value as $index => $val) {

          $sort[$index] = $val[$subkey];

      }

      

      asort($sort);

      

      $keys = array_keys($sort);

      $newValue = array();

      foreach ($keys as $index) {

        if($keep_keys_in_sub)

            $newValue[$index] = $value[$index];

          else

            $newValue[] = $value[$index];

      }

      

      if($sort_descending)

        $value = array_reverse($newValue, $keep_keys_in_sub);

      else

        $value = $newValue;

    }

    

    $array = $temp_array;

  }

?>

down

-1

g8z at yahoo dot com ¶

18 years ago

<?php
/**
This sort function allows you to sort an associative array while "sticking" some fields.

$sticky_fields = an array of fields that should not be re-sorted. This is a method of achieving sub-sorts within contiguous groups of records that have common data in some fields.

Courtesy of the $5 Script Archive: http://www.tufat.com
**/

define( 'ASC_AZ', 1000 );
define( 'DESC_AZ', 1001 );
define( 'ASC_NUM', 1002 );
define( 'DESC_NUM', 1003 );

function stickysort( $arr, $field, $sort_type, $sticky_fields = array() ) {
    $i = 0;
    foreach ($arr as $value) {
        $is_contiguous = true;
        if(!empty($grouped_arr)) {
            $last_value = end($grouped_arr[$i]);

            if(!($sticky_fields == array())) {
                foreach ($sticky_fields as $sticky_field) {
                    if ($value[$sticky_field] <> $last_value[$sticky_field]) {
                        $is_contiguous = false;
                        break;
                    }
                }
            }
        }
        if ($is_contiguous)
            $grouped_arr[$i][] = $value;
        else
            $grouped_arr[++$i][] = $value;
    }
    $code = '';
    switch($sort_type) {
        case ASC_AZ:
            $code .= 'return strcasecmp($a["'.$field.'"], $b["'.$field.'"]);';
            break;
        case DESC_AZ:
            $code .= 'return (-1*strcasecmp($a["'.$field.'"], $b["'.$field.'"]));';
            break;
        case ASC_NUM:
            $code .= 'return ($a["'.$field.'"] - $b["'.$field.'"]);';
            break;
        case DESC_NUM:
            $code .= 'return ($b["'.$field.'"] - $a["'.$field.'"]);';
            break;
    }

    $compare = create_function('$a, $b', $code);

    foreach($grouped_arr as $grouped_arr_key=>$grouped_arr_value)
        usort ( $grouped_arr[$grouped_arr_key], $compare );

    $arr = array();
    foreach($grouped_arr as $grouped_arr_key=>$grouped_arr_value)
        foreach($grouped_arr[$grouped_arr_key] as $grouped_arr_arr_key=>$grouped_arr_arr_value)
            $arr[] = $grouped_arr[$grouped_arr_key][$grouped_arr_arr_key];

    return $arr;
}
?>

down

-1

raul at jimi dot com dot mx ¶

19 years ago

I had an array like this:
$arr=array (1,4,3,6,5);

which returns this:
$arr[0]=1
$arr[1]=4
$arr[2]=3
$arr[3]=6
$arr[4]=5

But lets say i remove [2] which is number 3, i get:

$arr[0]=1
$arr[1]=4
$arr[3]=6
$arr[4]=5

And i want to reindex without doing a sort because i dont want to lose the order of the numbers (like a pop in a stack but in the middle of the list), i do this:

$arr=array_chunk($arr,count($arr));
$arr=$arr[0];

the result is:

$arr[0]=1
$arr[1]=4
$arr[2]=6
$arr[3]=5

This can be applied mostly for tree sorting, when you only have the id and the parent values of the node, and you want to have N levels.

down

-1

poulou_0 at hotmail dot com ¶

14 years ago

if you are not interested in high or low case sort

<?php
//where
$sortable_array[$k] = $v2; 
//put
$sortable_array[$k] = strtolower($v2);

//and where
$sortable_array[$k] = $v;
//put
$sortable_array[$k] = strtolower($v);
?>

down

-1

g8z at yahoo dot com ¶

18 years ago

<?php
/**
This sort function allows you to sort an associative array while "sticking" some fields.

$sticky_fields = an array of fields that should not be re-sorted. This is a method of achieving sub-sorts within contiguous groups of records that have common data in some fields.

For example:

$a = array();

$a []= array(
    'name'         => 'Sam',
    'age'         => 23,
    'hire_date'    => '2004-01-01'
);
$a []= array(
    'name'        => 'Sam',
    'age'        => 44,
    'hire_date'    => '2003-03-23'
);
$a []= array(
    'name'        => 'Jenny',
    'age'        => 20,
    'hire_date' => '2000-12-31'
);
$a []= array(
    'name'        => 'Samantha',
    'age'        => 50,
    'hire_date' => '2000-12-14'
);

$sticky_fields = array( 'name' );
print_r( stickysort( $a, 'age', DESC_NUM, $sticky_fields ) );

OUTPUT:

Array
(
    [0] => Array
        (
            [name] => Sam
            [age] => 44
            [hire_date] => 2003-03-23
        )
    [1] => Array
        (
            [name] => Sam
            [age] => 23
            [hire_date] => 2004-01-01
        )
    [2] => Array
        (
            [name] => Jenny
            [age] => 20
            [hire_date] => 2000-12-31
        )
    [3] => Array
        (
            [name] => Samantha
            [age] => 50
            [hire_date] => 2000-12-14
        )
)

Here's why this is the correct output - the "name" field is sticky, so it cannot change its sort order. Thus, the "age" field is only sorted as a sub-sort within records where "name" is identical. Thus, the "Sam" records are reversed, because 44 > 23, but Samantha remains at the bottom, even though her age is 50. This is a way of achieving "sub-sorts" and "sub-sub-sorts" (and so on) within records of identical data for specific fields.

Courtesy of the $5 Script Archive: http://www.tufat.com
**/

define( 'ASC_AZ', 1000 );
define( 'DESC_AZ', 1001 );
define( 'ASC_NUM', 1002 );
define( 'DESC_NUM', 1003 );

function stickysort( $arr, $field, $sort_type, $sticky_fields = array() ) {
    $i = 0;
    foreach ($arr as $value) {
        $is_contiguous = true;
        if(!empty($grouped_arr)) {
            $last_value = end($grouped_arr[$i]);

            if(!($sticky_fields == array())) {
                foreach ($sticky_fields as $sticky_field) {
                    if ($value[$sticky_field] <> $last_value[$sticky_field]) {
                        $is_contiguous = false;
                        break;
                    }
                }
            }
        }
        if ($is_contiguous)
            $grouped_arr[$i][] = $value;
        else
            $grouped_arr[++$i][] = $value;
    }
    $code = '';
    switch($sort_type) {
        case ASC_AZ:
            $code .= 'return strcasecmp($a["'.$field.'"], $b["'.$field.'"]);';
            break;
        case DESC_AZ:
            $code .= 'return (-1*strcasecmp($a["'.$field.'"], $b["'.$field.'"]));';
            break;
        case ASC_NUM:
            $code .= 'return ($a["'.$field.'"] - $b["'.$field.'"]);';
            break;
        case DESC_NUM:
            $code .= 'return ($b["'.$field.'"] - $a["'.$field.'"]);';
            break;
    }

    $compare = create_function('$a, $b', $code);

    foreach($grouped_arr as $grouped_arr_key=>$grouped_arr_value)
        usort ( $grouped_arr[$grouped_arr_key], $compare );

    $arr = array();
    foreach($grouped_arr as $grouped_arr_key=>$grouped_arr_value)
        foreach($grouped_arr[$grouped_arr_key] as $grouped_arr_arr_key=>$grouped_arr_arr_value)
            $arr[] = $grouped_arr[$grouped_arr_key][$grouped_arr_arr_key];

    return $arr;
}
?>

down

-2

Brecht Cloetens ¶

15 years ago

<?php
    
/**
 * function: array_columns
 * author: Brecht Cloetens
 * params: $a = array() // original array
 *         $c = int() // number of columns
 */
function array_columns(&$a, $c=2)
{
    $m = ceil(count($a)/$c);
    $j = 0;
    for($i=0; $i<$m; $i++) {
        for($k=0; $k<$c; $k++) {
            $key = $i+($m*$k);
            settype($key,'integer');
            if(array_key_exists($key,$a)) {
                $b[$j] = $a[$key];
                $j++;
            }
        }
    }
    $a = $b;
}

$arr = range('a','z');
array_columns($arr,4);
print_r($arr);

?>

Example:
array(1,2,3,4,5) will be converted to array(1,4,2,5,3);

This can be easy if you want to display an array into a specified number of columns.

<table>
    <tr>
        <td>$arr[0] => 1</td>
        <td>$arr[1] => 4</td>
    </tr>
    <tr>
        <td>$arr[2] => 2</td>
        <td>$arr[3] => 5</td>
    </tr>
    <tr>
        <td>$arr[4] => 3</td>
        <td></td>
    </tr>
</table>

down

-1

www at designdetector dot com ¶

16 years ago

To sort an array of multiple text fields alphabetically you have to make the text lowercase before sorting the array. Otherwise PHP puts acronyms before words. You can see this in my example code. Simply store the original text field at the end of the array line and call it later from there. You can safely ignore the lowercase version which is added to the start of the array line.

<?php
echo '<pre>ORIGINAL DATA:
<br />';

$data = array(
'Saturn|7|8|9|0||',
'Hello|0|1|2|3||',
'SFX|5|3|2|4||',
'HP|9|0|5|6||'
);

print_r($data);

sort($data);
reset($data);

echo '<br />RAW SORT:
<br />';

print_r($data);

for ($c = 0; $c < count($data); $c++) {
    list ($letter,$g1,$g2,$g3,$g4,$end) = explode ('|', $data[$c]);
    $lowercase = strtolower($letter);
    $data2[$c] = array($lowercase,$g1,$g2,$g3,$g4,$letter);
}

sort($data2);
reset($data2);

echo '<br />LOWERCASE SORT:
<br />';

print_r($data2);

echo '</pre>';
?>

down

-3

sinan at sinaneldem dot com ¶

17 years ago

here is little script which will merge arrays, remove duplicates and sort it by alphabetical order:

<?php

$array1 = array('apple', 'banana','pear');
$array2 = array('grape', 'pear','orange');

function array_unique_merge_sort($array1, $array2){
$array = array_unique(array_merge($array1, $array2));
sort($array);
foreach ($array as $key => $value) {
    $new[$key] = $value;
}
return $new;
}

print_r (array_unique_merge_sort($array1, $array2));

?>

this will print out:

Array ( [0] => apple [1] => banana [2] => grape [3] => orange [4] => pear )

down

-3

anaz114119 at gmail dot com ¶

14 years ago

sort from textfile by coloumn

example name||date||time||comments

if you want to sort by date

$column = 2

<?php

function array_sort($array,$column){

 $column = $column-1;

 foreach($array as $line){

 $bits = explode("||",$line);

 $bits ="$bits[$column]**$line";

 $array1[]=$bits;

}

 asort($array1);

 foreach($array1 as $line){

 $bit = explode("**",$line);

 $bit ="$bit[1]";

 $array2[]=$bit;

}

 return$array2;

}

?>

down

-3

anthony at ectrolinux dot com ¶

20 years ago

In a brief addition to the previous poster's message, the ascending sorting order used by PHP directly corresponds to ISO-8859-1 (ASCII). Therefore the character \48 (numeral 0) would be placed before the character \82 (R), which would be placed before the character \110 (n), and so forth.

＋add a note

sort

Description

Parameters

Return Values

Changelog

Examples

Notes

See Also

Found A Problem?

User Contributed Notes 35 notes