array_keys
If you want to pass an argument like ENT_QUOTES to htmlentities, you can do the follow.
<?php
$array = array_map( 'htmlentities' , $array, array_fill(0 , count($array) , ENT_QUOTES) );
?>
The third argument creates an equal sized array of $array filled with the parameter you want to give with your callback function.
array_map
(PHP 4 >= 4.0.6, PHP 5)
array_map — Wendet eine Callback-Funktion auf die Elemente von Arrays an
Beschreibung
array_map() gibt ein Array mit allen Elementen von arr1 zurück, nachdem die Callback-Funktion callback auf jedes einzelne Element angewandt wurde. Die Anzahl Parameter, welche die Callback-Funktion callback akzeptiert, sollte der Anzahl der an array_map() übergebenen Arrays entsprechen.
Beispiel #1 array_map()
<?php
function cube($n)
{
return($n*$n*$n);
}
$a = array(1, 2, 3, 4, 5);
$b = array_map("cube", $a);
print_r($b);
?>
Dies speichert in $b:
Array ( [0] => 1 [1] => 8 [2] => 27 [3] => 64 [4] => 125 )
Beispiel #2 array_map() - Verwendung mehrerer Arrays
<?php
function show_Spanish($n, $m)
{
return("Die Zahl $n heißt auf Spanisch $m");
}
function map_Spanish($n, $m)
{
return(array($n => $m));
}
$a = array(1, 2, 3, 4, 5);
$b = array("uno", "dos", "tres", "cuatro", "cinco");
$c = array_map("show_Spanish", $a, $b);
print_r($c);
$d = array_map("map_Spanish", $a , $b);
print_r($d);
?>
Das oben gezeigte Beispiel erzeugt folgende Ausgabe:
// Ausgabe von $c Array ( [0] => Die Zahl 1 heißt auf Spanisch uno [1] => Die Zahl 2 heißt auf Spanisch dos [2] => Die Zahl 3 heißt auf Spanisch tres [3] => Die Zahl 4 heißt auf Spanisch cuatro [4] => Die Zahl 5 heißt auf Spanisch cinco ) // Ausgabe von $d Array ( [0] => Array ( [1] => uno ) [1] => Array ( [2] => dos ) [2] => Array ( [3] => tres ) [3] => Array ( [4] => cuatro ) [4] => Array ( [5] => cinco ) )
Bei Verwendung von zwei oder mehr Arrays sollten diese gewöhnlich die gleiche Länge besitzen, da die Callback-Funktion parallel auf die entsprechenden Elemente angewandt wird. Haben die Arrays unterschiedliche Längen, wird das kürzeste um leere Elemente erweitert.
Eine interessante Anwendung dieser Funktion ist die Konstruktion eines Arrays bestehend aus Arrays, was mit NULL als Name der Callback-Funktion leicht realisiert werden kann.
Beispiel #3 Erstellen eines Arrays mit Arrays
<?php
$a = array(1, 2, 3, 4, 5);
$b = array("eins", "zwei", "drei", "vier", "fünf");
$c = array("uno", "dos", "tres", "cuatro", "cinco");
$d = array_map(null, $a, $b, $c);
print_r($d);
?>
Das oben gezeigte Beispiel erzeugt folgende Ausgabe:
Array ( [0] => Array ( [0] => 1 [1] => eins [2] => uno ) [1] => Array ( [0] => 2 [1] => zwei [2] => dos ) [2] => Array ( [0] => 3 [1] => drei [2] => tres ) [3] => Array ( [0] => 4 [1] => vier [2] => cuatro ) [4] => Array ( [0] => 5 [1] => fünf [2] => cinco ) )
Siehe auch array_filter(), array_reduce(), array_walk(), create_function() und Informationen über den Callback-Typ.
add a note
User Contributed Notesarray_map
stijnleenknegt at gmail dot com
22-Jul-2008 04:17
22-Jul-2008 04:17
GUI
26-Jun-2008 07:48
26-Jun-2008 07:48
The following takes an array of objects, and returns the result of calling a member function on each object. So if I have an array of objects that all have a getName() method, calling array_map_objects("getName", $thingies) will return the array filled with the getName() value for each object.
<?php
function array_map_objects($member_function, $array) {
$values = array();
if(is_string($member_function) && is_array($array)) {
$callback = create_function('$e', 'return call_user_func(array($e, "' . $member_function .'"));');
$values = array_map($callback, $array);
}
return $values;
}
?>
BloodElf
27-Apr-2008 06:32
27-Apr-2008 06:32
Here is a simple way to highlight the matched words in the search results:
<?php
function highlight($word) {
static $num = 1;
return '<span class="word' . $num++ . '">' . $word . '</span>';
}
$text = "ala bala nica turska panica";
$search = "bala turska";
$words = explode(' ', $search);
echo str_replace($words, array_map("highlight", $words), $text);
moester at gmail dot com
02-Apr-2008 02:21
02-Apr-2008 02:21
Wish this was built in. Mimics Ruby and Prototype's array pluck function. Returns specific key/column from an array of objects.
<?php
function array_pluck($key, $array)
{
if (is_array($key) || !is_array($array)) return array();
$funct = create_function('$e', 'return is_array($e) && array_key_exists("'.$key.'",$e) ? $e["'. $key .'"] : null;');
return array_map($funct, $array);
}
// usage:
$a = array(array("id"=>10, "name"=>"joe"), array("id"=>11, "name"=>"bob"));
$ids = array_pluck("id", $a); // == array(10,11)
$names = array_pluck("name", $a); // == array("joe", "bob")
//works on non-keyed arrays also:
$a = array(array(3,4), array(5,6));
$col2 = array_pluck(1,$a); // == array(4,6) (grab 2nd column of data)
?>
chreekat
12-Mar-2008 04:48
12-Mar-2008 04:48
I was miffed that array_map didn't have a way to pass values *and* keys to the callback, but then I realized I could do this:
function callback($k, $v) { ... }
array_map( "callback", array_keys($array), $array);
jo at ho dot nl
17-Feb-2008 02:10
17-Feb-2008 02:10
Could also use things like...
array_keys(); and array_values(); offcourse...
However it's just an example off recursion via this function..
Which I found pretty handy at times dealing with arrays..
could also use:
<?php
call_user_func(array($this, __FUNCTION), $args);
?>
or
<?php
call_user_fuc_array(array($this, __FUNCTION__), $array);
?>
or
<?php
class{
public function __construct($arg){
if(is_array($arg)){
new self($arg);
}
else{
echo $arg.'<br/>'.PHP_EOL;
}
}
}
?>
Anyway.. plenty off examples..
It was just an idea for others...
avartabedian at webservice dot com dot uy
08-Feb-2008 05:39
08-Feb-2008 05:39
loaded67 at hotmail dot com, there is a little error in the add func params values.
Warning: Missing argument 2 for test::add(), called in /tmp/test.php on line 34 and defined in /tmp/test.php on line 6
Array => <br/>
now it runs...
<?php
class test{
//private $container = array();
final public function add($key, $value=NULL){
/* params values fix */
$value = $value==NULL?$key:$value;
/* recursion */
if(is_array($value)){
array_map(array($this, __FUNCTION__), array_keys($value), array_values($value));
}
/* procedural */
else{
echo $key.' => '.$value.'<br/>'.PHP_EOL;
// do stuff...
// if(!isset($this->container[$key])){
// $this->container[$key] = $value;
// }
//else{ // trigger_error() xor throw new Exception?
// echo 'allready exists!<br/>'.PHP_EOL;
//}
}
}
}
//
$array = array (
'one' => 'value1',
'two' => 'value2',
'three' => 'value3'
);
$t = new test;
$t->add($array);
?>
good luck!
loaded67 at hotmail dot com
08-Feb-2008 02:59
08-Feb-2008 02:59
this function is really nice for recursion in php!!!
example in a class:
<?php
class test{
//private $container = array();
final public function add($key, $value){
/* recursion */
if(is_array($value)){
array_map(array($this, __FUNCTION__), array_keys($value), array_values($value));
}
/* procedural */
else{
echo $key.' => '.$value.'<br/>'.PHP_EOL;
// do stuff...
// if(!isset($this->container[$key])){
// $this->container[$key] = $value;
// }
//else{ // trigger_error() xor throw new Exception?
// echo 'allready exists!<br/>'.PHP_EOL;
//}
}
}
}
//
$array = array (
'one' => 'value1',
'two' => 'value2',
'three' => 'value3'
);
$t = new test;
$t->add($array);
?>
you could easiely do this without a class too offcourse!
used in php 5.2.5
pmf
22-Jan-2008 07:02
22-Jan-2008 07:02
This function behaves exactly like array_map but additionally does not reject non-array arguments. Instead, it transforms them with the array_fill function to a constant valued array of required length according to the other array arguments (if any) and executes the original array_map function.
<?php
function array_map2() {
$args = func_get_args();
$callback = array_shift($args);
$args = array_map(
create_function('$a,$max','return is_array($a)? $a: array_fill(0,$max,$a);'),
$args,array_fill(0,count($args),array_reduce($args,
create_function('$v,$w','return max($v,is_array($w)? count($w): 1);'))));
array_unshift($args,$callback);
return call_user_func_array("array_map",$args);
}
?>
Example:
<?php
$get = "first=value1&second=value2&third=value3";
print_r(array_map2("explode","=",explode("&",$get)));
?>
would print out:
<?php
Array
(
[0] => Array
(
[0] => first
[1] => value1
)
[1] => Array
(
[0] => second
[1] => value2
)
[2] => Array
(
[0] => third
[1] => value3
)
)
?>
/pmf
henrique at webcoder dot com dot br
01-Nov-2007 09:02
01-Nov-2007 09:02
Adding method support to function by Andref (multidimensionalArrayMap).
function array_map_r( $func, $arr )
{
$newArr = array();
foreach( $arr as $key => $value )
{
$newArr[ $key ] = ( is_array( $value ) ? array_map_r( $func, $value ) : ( is_array($func) ? call_user_func_array($func, $value) : $func( $value ) ) );
}
return $newArr;
}
array_map_r('function', array());
or
array_map_r(array('class', 'method'), array());
bturchik at iponweb dot net
19-Jul-2007 07:46
19-Jul-2007 07:46
Maybe this one will be useful for someone:
function array_map_helper($mapper, $array) {
$mapper = preg_replace('/^return (.*?);$/', '$1', trim($mapper));
$result = array();
if (preg_match('/(\(?)(.*?)\s*=>\s*(.*?)(\)?)$/', $mapper, $matches)) {
list($full_found, $array_open, $left, $right, $array_close) = $matches;
if ($array_open && $array_close) {
$mapper = '$result[] = array' . $full_found . ';';
} else {
$mapper = '$result[' . $left . '] = ' . $right . ';';
}
} else {
$mapper = '$result[] = ' . $mapper . ';';
}
foreach ($array as $key => $value) {
eval($mapper);
}
return $result;
}
should be used like:
$array = array(array('foo' => 11, 'bar' => 22),
array('foo' => 111, 'bar' => 222),
array('foo' => 1111, 'bar' => 2222));
$mapped = array_map_helper('$value["foo"] => $value["bar"]', $array);
var_dump will give
array(3) {
[11]=>
int(22)
[111]=>
int(222)
[1111]=>
int(2222)
}
or
$mapped = array_map_helper('$value["foo"]', $array);
var_dump will give
array(3) {
[0]=>
int(11)
[1]=>
int(111)
[2]=>
int(1111)
}
or
$mapped = array_map_helper('$value["foo"] + $value["bar"] . " at position $key"', $array);
var_dump will give
array(3) {
[0]=>
string(16) "33 at position 0"
[1]=>
string(17) "333 at position 1"
[2]=>
string(18) "3333 at position 2"
}
andref dot dias at pronus dot eng dot br
24-Oct-2006 12:14
24-Oct-2006 12:14
A recursive way to handle multidimensional arrays:
<?php
function multidimensionalArrayMap( $func, $arr )
{
$newArr = array();
foreach( $arr as $key => $value )
{
$newArr[ $key ] = ( is_array( $value ) ? multidimensionalArrayMap( $func, $value ) : $func( $value ) );
}
return $newArr;
}
?>
pcdinh at phpvietnam dot net
17-Mar-2006 08:50
17-Mar-2006 08:50
Hi benjaminhill,
You can apply a method of a instantiated class to array_maps as follows:
class Maths {
function addOne($input) {
return ($input + 1);
}
}
$maths = new Maths();
$sum = array_map(array($maths, \\\'addOne\\\'), array(1, 2));
// where $maths is the object which has been instantiated before and addOne is its method without its own parameters
var_dump($sum);
The code fragment will return:
array
0 => 2
1 => 3
However, I love a syntax like this:
$sum = array_map($maths->addOne($this), array(1, 2));
where $this should be interpreted as each values extracted from the subsequent array, which in this case is array(1, 2).
This syntax reminds me of Javascript syntax.
PHP\\\'s callback mechanism should be improved.
26-Aug-2005 06:57
Here's a function, very helpfull to me, that allows you to map your callback on mixed args.
<?php
function array_smart_map($callback) {
// Initialization
$args = func_get_args() ;
array_shift($args) ; // suppressing the callback
$result = array() ;
// Validating parameters
foreach($args as $key => $arg)
if(is_array($arg)) {
// the first array found gives the size of mapping and the keys that will be used for the resulting array
if(!isset($size)) {
$keys = array_keys($arg) ;
$size = count($arg) ;
// the others arrays must have the same dimension
} elseif(count($arg) != $size) {
return FALSE ;
}
// all keys are suppressed
$args[$key] = array_values($arg) ;
}
// doing the callback thing
if(!isset($size))
// if no arrays were found, returns the result of the callback in an array
$result[] = call_user_func_array($callback, $args) ;
else
for($i=0; $i<$size; $i++) {
$column = array() ;
foreach($args as $arg)
$column[] = ( is_array($arg) ? $arg[$i] : $arg ) ;
$result[$keys[$i]] = call_user_func_array($callback, $column) ;
}
return $result ;
}
?>
Trying with :
<?php
// $_GET is ?foo=bar1-bar2-bar3&bar=foo1
print_r(array_smart_map('explode', '-', $_GET)) ;
?>
Returns :
array(
[foo] => array(
0 => bar1
1 => bar2
2 => bar3
)
[bar] => array(
1 => foo1
)
)
david dot tulloh at infaze dot com dot au
06-Jul-2005 04:53
06-Jul-2005 04:53
You can pass values to array_map by reference, essentially allowing you to use it as you would array_walk with multiple arrays as parameters.
A trivial example:
<?php
$a = array(1,2,3,4,5);
$add_func = create_function('&$x, $y', '$x+=$y;');
array_map($add_func, $a, $a);
print_r($a);
?>
Array
(
[0] => 2
[1] => 4
[2] => 6
[3] => 8
[4] => 10
)
Vinicius Cubas Brand
23-Mar-2005 05:31
23-Mar-2005 05:31
The following function does exaclty the same thing of array_map. However, maintains the same index of the input arrays
<?php
function array_map_keys($param1,$param2,$param3=NULL)
{
$res = array();
if ($param3 !== NULL)
{
foreach(array(2,3) as $p_name)
{
if (!is_array(${'param'.$p_name}))
{
trigger_error(__FUNCTION__.'(): Argument #'.$p_name.' should be an array',E_USER_WARNING);
return;
}
}
foreach($param2 as $key => $val)
{
$res[$key] = call_user_func($param1,$param2[$key],$param3[$key]);
}
}
else
{
if (!is_array($param2))
{
trigger_error(__FUNCTION__.'(): Argument #2 should be an array',E_USER_WARNING);
return;
}
foreach($param2 as $key => $val)
{
$res[$key] = call_user_func($param1,$param2[$key]);
}
}
return $res;
}
?>
For instance:
<?php
$arr1 = array(
'3' => 'a',
'4' => 'b',
'5' => 'c'
);
$arr2 = array(
'3' => 'd',
'4' => 'e',
'5' => 'f'
);
$arr3 = array_map_keys(create_function('$a,$b','return $a.$b;'),$arr1,$arr2);
print_r($arr3);
?>
The result will be:
Array
(
[3] => ad
[4] => be
[5] => cf
)
endofyourself at yahoo dot com
19-Feb-2005 11:29
19-Feb-2005 11:29
If you need to call a static method from array_map, this will NOT work:
<?PHP
array_map('myclass::myMethod' , $value);
?>
Instead, you need to do this:
<?PHP
array_map( array('myclass','myMethod') , $value);
?>
It is helpful to remember that this will work with any PHP function which expects a callback argument.
nd0 at gmx dot de
02-Jul-2004 04:42
02-Jul-2004 04:42
array_map works also fine with create_function:
<?php
$a = array(1, 2, 3, 4, 5);
$b = array_map(create_function('$n', 'return $n*$n*$n;'), $a);
print_r($b);
?>
if you want to manipulate the elements of the array, instead to on a copy,
than take a look at array_walk:
<?php
$a = array(1, 2, 3, 4, 5);
array_walk($a, create_function('&$n', '$n = $n*$n*$n;'));
print_r($a);
?>
The Result of both is:
Array
(
[0] => 1
[1] => 8
[2] => 27
[3] => 64
[4] => 125
)
bishop
09-Apr-2004 05:07
09-Apr-2004 05:07
Occasionally, you may find that you need to pull out a column (or several) from an array. Here's a map-like function to do that:
<?php
function &array_shear(&$arrays, $idx1 /* ... */) {
$indexes = func_get_args();
array_shift($indexes);
$newArrays = array ();
foreach (array_keys($arrays) as $arrayKey) {
$newArray = array ();
foreach ($indexes as $index) {
$newArray[$index] = $arrays[$arrayKey][$index];
unset($arrays[$arrayKey][$index]);
}
$newArrays[$arrayKey] = $newArray;
}
return $newArrays;
}
?>
So, doing this:
<?php
$t1 = array (
2 => array ('a', 'b', 'c'),
1 => array ('d', 'e', 'f'),
5 => array ('g', 'h', 'i'),
);
$t2 = array_shear($t1, 1, 0);
?>
will result in:
<?php
$t1 = array (
2 => array ( 2 => 'c', ),
1 => array ( 2 => 'f', ),
5 => array ( 2 => 'i', ),
);
$t2 = array (
2 => array ( 1 => 'b', 0 => 'a', ),
1 => array ( 1 => 'e', 0 => 'd', ),
5 => array ( 1 => 'h', 0 => 'g', ),
);
?>
stephen at mu dot com dot au
06-Jan-2003 10:02
06-Jan-2003 10:02
A note when doing something allong the lines of:
<?php
class foo {
var $var;
function bar() {
array_map(array($this, "baz"), array(1,2,3));
}
function baz($arg) {
$this->var = $this->var + $arg;
}
}
?>
This will *not* work as expected. You need to pass $this by reference as with:
array_map(array(&$this, "baz"), array(1,2,3));
or you'll be making a copy of the object each time, changing a value, then throwing the result away.
dan at mojavelinux dot com
14-Jun-2002 10:07
14-Jun-2002 10:07
Here is a better, more true version of a deep array_map. The only negative of this function is that the array is passed by reference, so just be aware of that. (patches welcome)
<?php
function array_map_deep(&$in_array, $in_func, $in_args = array(), $in_index = 1) {
// fix people from messing up the index of the value
if ($in_index < 1) {
$in_index = 1;
}
foreach (array_keys($in_array) as $key) {
// we need a reference, not a copy, normal foreach won't do
$value =& $in_array[$key];
// we need to copy args because we are doing
// manipulation on it farther down
$args = $in_args;
if (is_array($value)) {
array_map_deep($value, $in_func, $in_args, $in_index);
}
else {
array_splice($args, $in_index - 1, $in_index - 1, $value);
$value = call_user_func_array($in_func, $args);
}
}
return $in_array;
}
?>
This is a neat function because you can pass an array, a function, and an array of parameters, and finally, and index of where in the array of parameters for the callback function the contents you are mapping should get replaced. This index is human based (starts at 1), and can be used in something like a preg_replace callback, where the contents must be the 3rd index. Enjoy!