array_change_key_case
If you just want to grab one chunk from an array, you should use array_slice().
array_chunk
(PHP 4 >= 4.2.0, PHP 5)
array_chunk — Divide un array en fragmentos
Descripción
array array_chunk
( array
$input
, int $size
[, bool $preserve_keys = false
] )
Divide un array en fragmentos del tamaño definido en size.
El último fragmento puede contener menos elementos que size.
Parámetros
-
input -
Array para trabajar en
-
size -
El tamaño de cada fragmento.
-
preserve_keys -
Cuando se establece en
TRUElas keys serán preservadas. El valor por defecto esFALSElo cual reindexará los fragmentos numéricamente.
Valores devueltos
Retorna un array multidimensional indexado numéricamente, comenzando desde cero,
en el cual cada dimensión contiene la cantidad de elementos definida en size.
Errores/Excepciones
Si size es inferior a 1, una
E_WARNING será arrojada y NULL será retornado.
Ejemplos
Ejemplo #1 Ejemplo de array_chunk()
<?php
$input_array = array('a', 'b', 'c', 'd', 'e');
print_r(array_chunk($input_array, 2));
print_r(array_chunk($input_array, 2, true));
?>
El resultado del ejemplo sería:
Array
(
[0] => Array
(
[0] => a
[1] => b
)
[1] => Array
(
[0] => c
[1] => d
)
[2] => Array
(
[0] => e
)
)
Array
(
[0] => Array
(
[0] => a
[1] => b
)
[1] => Array
(
[2] => c
[3] => d
)
[2] => Array
(
[4] => e
)
)
add a note
User Contributed Notes
array_chunk
nate at ruggfamily dot com
19-Jul-2010 11:00
dead dot screamer at seznam dot cz
27-Jan-2009 03:28
This function can be used to reverse effect of <?php array_Chunk()?>.
<?php
function array_Unchunk($array)
{
return call_User_Func_Array('array_Merge',$array);
}
header('Content-Type: text/plain');
$array=array(
array(
'Black Canyon City',
'Chandler',
'Flagstaff',
'Gilbert',
'Glendale',
'Globe',
),
array(
'Mesa',
'Miami',
'Phoenix',
'Peoria',
'Prescott',
'Scottsdale',
),
array(
'Sun City',
'Surprise',
'Tempe',
'Tucson',
'Wickenburg',
),
);
var_Dump(array_Unchunk($array));
?>
Output:
array(17) {
[0]=>
string(17) "Black Canyon City"
[1]=>
string(8) "Chandler"
[2]=>
string(9) "Flagstaff"
[3]=>
string(7) "Gilbert"
[4]=>
string(8) "Glendale"
[5]=>
string(5) "Globe"
[6]=>
string(4) "Mesa"
[7]=>
string(5) "Miami"
[8]=>
string(7) "Phoenix"
[9]=>
string(6) "Peoria"
[10]=>
string(8) "Prescott"
[11]=>
string(10) "Scottsdale"
[12]=>
string(8) "Sun City"
[13]=>
string(8) "Surprise"
[14]=>
string(5) "Tempe"
[15]=>
string(6) "Tucson"
[16]=>
string(10) "Wickenburg"
}
Rasmus Schultz (http://mindplay.dk)
23-Jan-2009 02:59
Unfortunately, this function only accepts real arrays, not iterable objects... For that, you need this function:
<?php
function break_array($array, $page_size) {
$arrays = array();
$i = 0;
foreach ($array as $index => $item) {
if ($i++ % $page_size == 0) {
$arrays[] = array();
$current = & $arrays[count($arrays)-1];
}
$current[] = $item;
}
return $arrays;
}
?>
OIS
10-Jun-2008 07:31
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
08-May-2007 06:53
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( $citylist, 3 ) );
?>
Array
(
[0] => Array
(
[0] => Black Canyon City
[1] => Chandler
[2] => Flagstaff
[3] => Gilbert
[4] => Glendale
[5] => Globe
)
[1] => Array
(
[0] => Mesa
[1] => Miami
[2] => Phoenix
[3] => Peoria
[4] => Prescott
[5] => Scottsdale
)
[2] => Array
(
[0] => Sun City
[1] => Surprise
[2] => Tempe
[3] => Tucson
[4] => Wickenburg
)
)
21-Mar-2006 05:19
Here my array_chunk_values( ) with values distributed by lines (columns are balanced as much as possible) :
<?php
function array_chunk_vertical($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]', $value) ;
}
echo "\r\n" ;
}
/*
Output :
[ 1][ 6][11][16][20][24][28]
[ 2][ 7][12][17][21][25][29]
[ 3][ 8][13][18][22][26][30]
[ 4][ 9][14][19][23][27][31]
[ 5][10][15]
*/
?>
magick dit crow ot gmail dit com
16-Oct-2005 11:50
Mistake key did not do what I thought. A patch.
function array_bucket($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 $new_array;// return new array
}
magick dit crow ot gmail dit com
15-Oct-2005 12:58
This function takes each few elements of an array and averages them together. It then places the averages in a new array. It is used to smooth out data. For example lets say you have a years worth of hit data to a site and you want to graph it by the week. Then use a bucket of 7 and graph the functions output.
function array_bucket($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 $new_array; // return new smooth array
}
webmaster at cafe-clope dot net
20-Aug-2005 06:27
based on the same syntax, useful about making columns :
<?php
function array_chunk_fixed($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 05:21
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 05:02
[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;
}
}
?>