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array_combine> <array_change_key_case
Last updated: Fri, 15 Aug 2008

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array_chunk

(PHP 4 >= 4.2.0, PHP 5)

array_chunkSplittet ein Array in Teile auf

Beschreibung

array array_chunk ( array $input , int $size [, bool $preserve_keys ] )

array_chunk() teilt das Array in verschiedene Arrays mit size Werten auf. Am Ende kann auch ein Array mit weniger Werten erzeugt werden. Die Arrays werden als Teile eines mehrdimensionalen Arrays erzeugt, welches bei Null und beginnend numerisch indiziert ist.

Sie können PHP dazu zwingen, die originalen Schlüssel des Arrays input beizubehalten, indem Sie den optionalen Parameter preserve_keys auf TRUE setzen. Geben Sie FALSE an, werden in jedem erzeugten Array neue numerische Indizes erzeugt, welche bei Null beginnen. Default ist FALSE.

Beispiel #1 array_chunk()

<?php
$input_array 
= array('a''b''c''d''e');
print_r(array_chunk($input_array2));
print_r(array_chunk($input_array2true));
?>

Das oben gezeigte Beispiel erzeugt folgende Ausgabe:

Array
(
    [0] => Array
        (
            [0] => a
            [1] => b
        )

    [1] => Array
        (
            [0] => c
            [1] => d
        )

    [2] => Array
        (
            [0] => e
        )

)
Array
(
    [0] => Array
        (
            [0] => a
            [1] => b
        )

    [1] => Array
        (
            [2] => c
            [3] => d
        )

    [2] => Array
        (
            [4] => e
        )

)


array_combine> <array_change_key_case
Last updated: Fri, 15 Aug 2008
 
add a note add a note User Contributed Notes
array_chunk
OIS
10-Jun-2008 02:31
Response to azspot at gmail dot com function partition.

$columns = 3;
$citylist = array('Black Canyon City', 'Chandler', 'Flagstaff', 'Gilbert', 'Glendale', 'Globe', 'Mesa', 'Miami', 'Phoenix', 'Peoria', 'Prescott', 'Scottsdale', 'Sun City', 'Surprise', 'Tempe', 'Tucson', 'Wickenburg');
print_r(array_chunk($citylist, ceil(count($citylist) / $columns)));

Output:
Array
(
    [0] => Array
        (
            [0] => Black Canyon City
            [1] => Chandler
            [2] => Flagstaff
            [3] => Gilbert
            [4] => Glendale
            [5] => Globe
        )

    [1] => Array
        (
            [0] => Mesa
            [1] => Miami
            [2] => Phoenix
            [3] => Peoria
            [4] => Prescott
            [5] => Scottsdale
        )

    [2] => Array
        (
            [0] => Sun City
            [1] => Surprise
            [2] => Tempe
            [3] => Tucson
            [4] => Wickenburg
        )

)
azspot at gmail dot com
09-May-2007 01:53
Tried to use an example below (#56022) for array_chunk_fixed that would "partition" or divide an array into a desired number of split lists -- a useful procedure for "chunking" up objects or text items into columns, or partitioning any type of data resource. However, there seems to be a flaw with array_chunk_fixed — for instance, try it with a nine item list and with four partitions. It results in 3 entries with 3 items, then a blank array.

So, here is the output of my own dabbling on the matter:

<?php

function partition( $list, $p ) {
   
$listlen = count( $list );
   
$partlen = floor( $listlen / $p );
   
$partrem = $listlen % $p;
   
$partition = array();
   
$mark = 0;
    for (
$px = 0; $px < $p; $px++) {
       
$incr = ($px < $partrem) ? $partlen + 1 : $partlen;
       
$partition[$px] = array_slice( $list, $mark, $incr );
       
$mark += $incr;
    }
    return
$partition;
}

$citylist = array( "Black Canyon City", "Chandler", "Flagstaff", "Gilbert", "Glendale", "Globe", "Mesa", "Miami",
                  
"Phoenix", "Peoria", "Prescott", "Scottsdale", "Sun City", "Surprise", "Tempe", "Tucson", "Wickenburg" );
print_r( partition( $citylist, 3 ) );

?>

Array
(
    [0] => Array
        (
            [0] => Black Canyon City
            [1] => Chandler
            [2] => Flagstaff
            [3] => Gilbert
            [4] => Glendale
            [5] => Globe
        )

    [1] => Array
        (
            [0] => Mesa
            [1] => Miami
            [2] => Phoenix
            [3] => Peoria
            [4] => Prescott
            [5] => Scottsdale
        )

    [2] => Array
        (
            [0] => Sun City
            [1] => Surprise
            [2] => Tempe
            [3] => Tucson
            [4] => Wickenburg
        )

)
22-Mar-2006 01:19
Here my array_chunk_values( ) with values distributed by lines (columns are balanced as much as possible) :

<?php
   
function array_chunk_vertical($data, $columns) {
       
$n = count($data) ;
       
$per_column = floor($n / $columns) ;
       
$rest = $n % $columns ;

       
// The map
       
$per_columns = array( ) ;
        for (
$i = 0 ; $i < $columns ; $i++ ) {
           
$per_columns[$i] = $per_column + ($i < $rest ? 1 : 0) ;
        }

       
$tabular = array( ) ;
        foreach (
$per_columns as $rows ) {
            for (
$i = 0 ; $i < $rows ; $i++ ) {
               
$tabular[$i][ ] = array_shift($data) ;
            }
        }

        return
$tabular ;
    }

   
header('Content-Type: text/plain') ;

   
$data = array_chunk_vertical(range(1, 31), 7) ;
    foreach (
$data as $row ) {
        foreach (
$row as $value ) {
           
printf('[%2s]', $value) ;
        }
        echo
"\r\n" ;
    }

   
/*
        Output :

        [ 1][ 6][11][16][20][24][28]
        [ 2][ 7][12][17][21][25][29]
        [ 3][ 8][13][18][22][26][30]
        [ 4][ 9][14][19][23][27][31]
        [ 5][10][15]
    */
?>
magick dit crow ot gmail dit com
16-Oct-2005 06:50
Mistake key did not do what I thought. A patch.

function array_bucket($array,$bucket_size)// bucket filter
{
    if (!is_array($array)) return false;
    $buckets=array_chunk($array,$bucket_size);// chop up array into bucket size units
    $I=0;
    foreach ($buckets as $bucket)
    {
        $new_array[$I++]=array_sum($bucket)/count($bucket);
    }
    return $new_array;// return new array
}
magick dit crow ot gmail dit com
15-Oct-2005 07:58
This function takes each few elements of an array and averages them together. It then places the averages in a new array. It is used to smooth out data. For example lets say you have a years worth of hit data to a site and you want to graph it by the week. Then use a bucket of 7 and graph the functions output.

function array_bucket($array, $bucket_size)  // bucket filter
{
    if (!is_array($array)) return false; // no empty arrays
    $buckets=array_chunk($array,$bucket_size);  // chop up array into bucket size units
    foreach ($buckets as $bucket) $new_array[key($buckets])=array_sum($bucket)/count($bucket);
    return $new_array;  // return new smooth array
}
webmaster at cafe-clope dot net
21-Aug-2005 01:27
based on the same syntax, useful about making columns :

<?php
function array_chunk_fixed($input, $num, $preserve_keys = FALSE) {
   
$count = count($input) ;
    if(
$count)
       
$input = array_chunk($input, ceil($count/$num), $preserve_keys) ;
   
$input = array_pad($input, $num, array()) ;
    return
$input ;
}

$array = array(1, 2, 3, 4, 5) ;
print_r(array_chunk($array, 2)) ;
print_r(array_chunk_fixed($array, 2)) ;
?>

---- array_chunk : fixed number of sub-items ----
Array(
    [0] => Array(
            [0] => 1
            [1] => 2
        )
    [1] => Array(
            [0] => 3
            [1] => 4
        )

    [2] => Array(
            [0] => 5
        )
)

---- array_chunk : fixed number of columns ----
Array(
    [0] => Array(
            [0] => 1
            [1] => 2
            [2] => 3
        )
    [1] => Array(
            [0] => 4
            [1] => 5
        )
)
phpm at nreynolds dot me dot uk
17-Dec-2004 01:21
array_chunk() is helpful when constructing tables with a known number of columns but an unknown number of values, such as a calendar month. Example:

<?php

$values
= range(1, 31);
$rows = array_chunk($values, 7);

print
"<table>\n";
foreach (
$rows as $row) {
    print
"<tr>\n";
    foreach (
$row as $value) {
        print
"<td>" . $value . "</td>\n";
    }
    print
"</tr>\n";
}
print
"</table>\n";

?>

Outputs:

1 2 3 4 5 6 7
8 9 10 11 12 13 14
15 16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31

The other direction is possible too, with the aid of a function included at the bottom of this note. Changing this line:
  $rows = array_chunk($values, 7);

To this:
  $rows = array_chunk_vertical($values, 7);

Produces a vertical calendar with seven columns:

1 6  11 16 21 26 31
2 7  12 17 22 27
3 8  13 18 23 28
4 9  14 19 24 29
5 10 15 20 25 30

You can also specify that $size refers to the number of rows, not columns:
  $rows = array_chunk_vertical($values, 7, false, false);

Producing this:

1 8  15 22 29
2 9  16 23 30
3 10 17 24 31
4 11 18 25
5 12 19 26
6 13 20 27
7 14 21 28

The function:

<?php

function array_chunk_vertical($input, $size, $preserve_keys = false, $size_is_horizontal = true)
{
   
$chunks = array();
   
    if (
$size_is_horizontal) {
       
$chunk_count = ceil(count($input) / $size);
    } else {
       
$chunk_count = $size;
    }
   
    for (
$chunk_index = 0; $chunk_index < $chunk_count; $chunk_index++) {
       
$chunks[] = array();
    }

   
$chunk_index = 0;
    foreach (
$input as $key => $value)
    {
        if (
$preserve_keys) {
           
$chunks[$chunk_index][$key] = $value;
        } else {
           
$chunks[$chunk_index][] = $value;
        }
       
        if (++
$chunk_index == $chunk_count) {
           
$chunk_index = 0;
        }
    }
   
    return
$chunks;
}

?>
mick at vandermostvanspijk dot nl
07-Apr-2004 12:02
[Editors note: This function was based on a previous function by gphemsley at nospam users dot sourceforge.net]

For those of you that need array_chunk() for PHP < 4.2.0, this function should do the trick:

<?php
if (!function_exists('array_chunk')) {
    function
array_chunk( $input, $size, $preserve_keys = false) {
        @
reset( $input );
       
       
$i = $j = 0;

        while( @list(
$key, $value ) = @each( $input ) ) {
            if( !( isset(
$chunks[$i] ) ) ) {
              
$chunks[$i] = array();
            }

            if(
count( $chunks[$i] ) < $size ) {
                if(
$preserve_keys ) {
                   
$chunks[$i][$key] = $value;
                   
$j++;
                } else {
                   
$chunks[$i][] = $value;
                }
            } else {
               
$i++;

                if(
$preserve_keys ) {
                   
$chunks[$i][$key] = $value;
                   
$j++;
                } else {
                   
$j = 0;
                   
$chunks[$i][$j] = $value;
                }
            }
        }

        return
$chunks;
    }
}
?>

array_combine> <array_change_key_case
Last updated: Fri, 15 Aug 2008
 
 
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