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
)
)
array_chunk
(PHP 4 >= 4.2.0, PHP 5, PHP 7)
array_chunk — Desparte un tablou în porțiuni
Descrierea
array_chunk
( array
$array
, int $size
, bool $preserve_keys = false
) : array
Desparte un tablou în porțiuni de dimensiunea size.
Ultima porțiune poate să conțină mai puține elemente decât
size.
Parametri
-
array -
Tabloul cu care se lucrează
-
size -
Dimensiunea fiecărei porțiuni
-
preserve_keys -
Când este stabilit în
truecheile vor fi păstrate. Implicit setefalse, ceea ce va reindexa numeric porțiunea
Valorile întoarse
Întoarce un tablou multidimensional indexat numeric, începând cu zero,
fiecare dimensiune conținând size elemente.
Erori/Excepții
Dacă size este mai mic decât 1 va fi emisă o eroare
E_WARNING și se va întoarce null.
Exemple
Example #1 Exemplu 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));
?>
Exemplul de mai sus va afișa:
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 20 notes
azspot at gmail dot com ¶
17 years ago
Andrew Martin ¶
6 years ago
To reverse an array_chunk, use array_merge, passing the chunks as a variadic:
<?php
$array = [1, 2, 3, 4, 5, 6, 7, 8, 9];
$chunks = array_chunk($array, 3);
// $chunks = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
$de_chunked = array_merge(…$chunks);
// $de_chunked = [1, 2, 3, 4, 5, 6, 7, 8, 9]
?>
suisuiruyi at aliyun dot com ¶
8 years ago
chunk array vertically
$arr = range(1, 19);
function array_chunk_vertical($arr, $percolnum){
$n = count($arr);
$mod = $n % $percolnum;
$cols = floor($n / $percolnum);
$mod ? $cols++ : null ;
$re = array();
for($col = 0; $col < $cols; $col++){
for($row = 0; $row < $percolnum; $row++){
if($arr){
$re[$row][] = array_shift($arr);
}
}
}
return $re;
}
$result = array_chunk_vertical($arr, 6);
foreach($result as $row){
foreach($row as $val){
echo '['.$val.']';
}
echo '<br/>';
}
/*
[1][7][13][19]
[2][8][14]
[3][9][15]
[4][10][16]
[5][11][17]
[6][12][18]
*/
Anonymous ¶
18 years ago
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]
*/
?>
nate at ruggfamily dot com ¶
14 years ago
If you just want to grab one chunk from an array, you should use array_slice().
dustin at fivetechnology dot com ¶
8 years ago
Had need to chunk an object which implemented ArrayAccess Iterator Countable. array_chunk wouldn't do it. Should work for any list of things
<?php
$listOfThings = array(1,2,3,4,5,6,7,8,9,10,11,12,13);
print_r(chunk_iterable($listOfThings, 4);
function chunk_iterable($listOfThings, $size) {
$chunk = 0;
$chunks = array_fill(0, ceil(count($listOfThings) / $size) - 1, array());
$index = 0;
foreach($listOfThings as $thing) {
if ($index && $index % $size == 0) $chunk++;
$chunks[$chunk][] = $thing;
$index++;
}
return $chunks;
}
?>
siddharthundare at gmail dot com ¶
9 years ago
<table>
<tr>
<?php
$array_chunkdata = array(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);
$chunk = array_chunk($array_chunkdata,5);
$rev_counter = 2;
function for_chunk($chunk_data){
echo "<td><table>";
foreach($chunk_data as $key => $chunk_value)
{
echo "<tr><td>";
echo $chunk_value;
echo "</td></tr>";
}
echo "</table></td>";
}
foreach($chunk as $key => $chunk_data)
{
if($rev_counter%2==0)
{
for_chunk($chunk_data);
}
else
{
$chunk_data = array_reverse($chunk_data);
for_chunk($chunk_data);
}
$rev_counter++;
}
?>
</tr>
</table>
/*
Output:
1
2
3
4
5
10
9
8
7
6
11
12
13
14
15
20
19
18
17
16
21
22
23
24
25
*/
Anonymous ¶
3 years ago
Most easy way split array to parts
<?php
$arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
print_r(array_chunk($arr, ceil(count($arr) / 2)));
// return: [[1, 2, 3, 4, 5], [6, 7, 8, 9, 10]]
print_r(array_chunk($arr, ceil(count($arr) / 3)));
// return: [[1, 2, 3, 4], [5, 6, 7, 8], [9, 10]]
?>
OIS ¶
16 years ago
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
)
)
phpm at nreynolds dot me dot uk ¶
20 years ago
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;
}
?>
stratboy ¶
11 years ago
Hi, I've made a function to split an array into chunks based on columns wanted. For example:
<?php $a = array(1,2,3,4,5,6,7,8); ?>
goal (say, for 3 columns):
<?php
array(
array(1,2,3),
array(4,5,6),
array(7,8)
);
?>
<?php
function get_array_columns($array, $columns){
$columns_map = array();
for($i=0; $i<$columns; $i++){ $columns_map[] = 0; }//init columns
//create map
$count = count($array);
$position = 0;
while($count > 0){
$columns_map[$position]++;
$position = ($position < $columns-1) ? ++$position : 0;
$count--;
}
//chunk the array based on map
$chunked = array();
foreach($columns_map as $map){
$chunked[] = array_splice($array,0,$map);
}
return $chunked;
}//end get_array_columns
?>
mick at vandermostvanspijk dot nl ¶
20 years ago
[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 $chunks;
}
}
?>
dead dot screamer at seznam dot cz ¶
15 years ago
This function can be used to reverse effect of <?php array_Chunk()?>.
<?php
function array_Unchunk($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"
}
magick dit crow ot gmail dit com ¶
19 years ago
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 $new_array; // return new smooth array
}
normiridium at gmail dot com ¶
8 years ago
A breakdown by groups with excess:
function array_chunk_greedy($arr, $count){
$arr = array_chunk($arr, $count);
if(($k = count($arr)-1) > 0){
if(count($arr[$k]) < $count){
$arr[$k-1] = array_merge($arr[$k-1], $arr[$k]);
unset($arr[$k]);
}
}
return $arr;
}
$arr = range(1, 13);
$arr = array_chunk_greedy($arr, 4);
print_r($arr);
[1,2,3,4,5,6,7,8,9,10,11,12,13] —> [1,2,3,4] [5,6,7,8] [9,10,11,12,13]
More examples:
[1,2,3,4,5,6,7,8,9,10,11,12] —> [1,2,3,4] [5,6,7,8] [9,10,11,12]
[1,2,3,4,5,6,7,8,9,10,11,12,13] —> [1,2,3,4] [5,6,7,8] [9,10,11,12,13]
[1,2,3,4,5,6,7,8,9,10,11,12,13,14] —> [1,2,3,4] [5,6,7,8] [9,10,11,12,13,14]
[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15] —> [1,2,3,4] [5,6,7,8] [9,10,11,12,13,14,15]
[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16] —> [1,2,3,4] [5,6,7,8] [9,10,11,12] [13,14,15,16]
Example report:
$arr = range(1, 45);
$arr = array_chunk_lazy($arr, 10);
$arr = array_map(function($sub_value) {
return implode('<br>', $sub_value);
}, $arr);
$title = '<h2>title</h2>';
$arr = $title.implode($title, $arr).$title;
echo $arr;
leon at valkenb dot org ¶
3 years ago
With no luck finding a function; here is the one I wrote:
It will evenly distribute items into a fixed amount of groups but also keeps items that were sorted close together to be in the same output groups.
<?php
function distributed_array_chunk(array $items, int $groups, bool $preserveKeys = false) {
$grouped = [];
$groupsPerItem = $groups / count($items);
$progress = 0.00;
foreach ($items as $key => $value) {
$index = floor($progress += $groupsPerItem);
if ($preserveKeys) {
$grouped[$index][$key] = $value;
}
else{
$grouped[$index][] = $value;
}
}
return $grouped;
}
?>
webmaster at cafe-clope dot net ¶
19 years ago
based on the same syntax, useful about making columns :
<?php
function array_chunk_fixed($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($array, 2)) ;
?>
---- array_chunk : fixed number of sub-items ----
Array(
[0] => Array(
[0] => 1
[1] => 2
)
[1] => Array(
[0] => 3
[1] => 4
)
[2] => Array(
[0] => 5
)
)
---- array_chunk : fixed number of columns ----
Array(
[0] => Array(
[0] => 1
[1] => 2
[2] => 3
)
[1] => Array(
[0] => 4
[1] => 5
)
)
magick dit crow ot gmail dit com ¶
19 years ago
Mistake key did not do what I thought. A patch.
function array_bucket($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 $new_array;// return new array
}
Anonymous ¶
10 years ago
Couldn't get the array_chunk_values() working, so ended up with this implementation:
<?php
function array_chunk_columns($data, $num_columns) {
$n = count($data);
$per_column = floor($n / $num_columns);
$rest = $n % $num_columns;
$columns = array();
$index = 0;
for ($i = 0; $i < $num_columns; $i++) {
// Add an extra item to each column while the column number is less than the
// remainder.
$add_rest = ($rest && ($i < $rest)) ? 1 : 0;
$number = $per_column + $add_rest;
$columns[] = array_slice($data, $index, $number);
$index += $number;
}
return $columns;
}
?>
Rasmus Schultz (http://mindplay.dk) ¶
15 years ago
Unfortunately, this function only accepts real arrays, not iterable objects... For that, you need this function:
<?php
function break_array($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;
}
?>
