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array_filter — Filtert Elemente eines Arrays mittels einer Callback-Funktion
Iteriert über jeden Wert im Array input und übergibt diesen der Callbackfunktion callback. Gibt die Funktion callback true zurück, so wird der aktuelle Wert von input in das Ergebnis-Array geschrieben. Die Schlüssel des Arrays bleiben erhalten.
Das Array, über das iteriert werden soll
Die zu verwendende Callbackfunktion
Falls die Funktion callback nicht angegeben wurde, werden alle Einträge des Arrays entfernt, die FALSE sind. Schauen Sie sich Konvertierung in Booleans für mehr Informationen hierzu an.
Gibt das gefilterte Array zurück.
Beispiel #1 array_filter()-Beispiel
<?php
function ungerade($var)
{
return($var & 1);
}
function gerade($var)
{
return(!($var & 1));
}
$array1 = array("a"=>1, "b"=>2, "c"=>3, "d"=>4, "e"=>5);
$array2 = array(6, 7, 8, 9, 10, 11, 12);
echo "Ungerade :\n";
print_r(array_filter($array1, "ungerade"));
echo "Gerade:\n";
print_r(array_filter($array2, "gerade"));
?>
Das oben gezeigte Beispiel erzeugt folgende Ausgabe:
Ungerade :
Array
(
[a] => 1
[c] => 3
[e] => 5
)
Gerade:
Array
(
[0] => 6
[2] => 8
[4] => 10
[6] => 12
)
Beispiel #2 array_filter() ohne callback
<?php
$entry = array(
0 => 'foo',
1 => false,
2 => -1,
3 => null,
4 => ''
);
print_r(array_filter($entry));
?>
Das oben gezeigte Beispiel erzeugt folgende Ausgabe:
Array
(
[0] => foo
[2] => -1
)
Wird das Array durch die Callbackfunktion verändert (z.B. hinzufügen oder löschen von Elementen oder ein unset-Aufruf), so ist das Verhalten dieser Funktion undefiniert.
I built the following array_remove_keys() function to
remove one or more keys from an array.
<?php
function array_remove_keys($array, $keys = array()) {
// If array is empty or not an array at all, don't bother
// doing anything else.
if(empty($array) || (! is_array($array))) {
return $array;
}
// If $keys is a comma-separated list, convert to an array.
if(is_string($keys)) {
$keys = explode(',', $keys);
}
// At this point if $keys is not an array, we can't do anything with it.
if(! is_array($keys)) {
return $array;
}
// array_diff_key() expected an associative array.
$assocKeys = array();
foreach($keys as $key) {
$assocKeys[$key] = true;
}
return array_diff_key($array, $assocKeys);
}
// Example:
$data = array(
'name' => 'Brian',
'address1' => '98 Market St.',
'address2' => 'N/A'
);
// Output before array_remove_keys()
var_dump($data);
// Remove address2 key.
$data = array_remove_keys($data, 'address2');
// Output after array_remove_keys()
var_dump($data);
/* Output:
array(3) {
["name"]=>
string(5) "Brian"
["address1"]=>
string(13) "98 Market St."
["address2"]=>
string(3) "N/A"
}
array(2) {
["name"]=>
string(5) "Brian"
["address1"]=>
string(13) "98 Market St."
}
*/
?>
Here is how you could easily delete a specific value from an array with array_filter:
<?php
$array = array (1, 3, 3, 5, 6);
$my_value = 3;
$filtered_array = array_filter($array, function ($element) use ($my_value) { return ($element != $my_value); } );
print_r($filtered_array);
?>
output:
Array
(
[0] => 1
[3] => 5
[4] => 6
)
Because array_filter() preserves keys, you should consider the resulting array to be an associative array even if the original array had integer keys for there may be holes in your sequence of keys. This means that, for example, json_encode() will convert your result array into an object instead of an array. Call array_values() on the result array to guarantee json_encode() gives you an array.
A function that allows filtering an array by keys:
<?php
function array_filter_key( $input, $callback ) {
if ( !is_array( $input ) ) {
trigger_error( 'array_filter_key() expects parameter 1 to be array, ' . gettype( $input ) . ' given', E_USER_WARNING );
return null;
}
if ( empty( $input ) ) {
return $input;
}
$filteredKeys = array_filter( array_keys( $input ), $callback );
if ( empty( $filteredKeys ) ) {
return array();
}
$input = array_intersect_key( array_flip( $filteredKeys ), $input );
return $input;
}
?>
Example:
<?php
$input = array_flip( range( 'a', 'z' ) );
$consonants = array_filter_key( $arr, function( $elem ) {
$vowels = "aeiou";
return strpos( $vowels, strtolower( $elem ) ) === false;
} );
?>
Outputs:
array(21) {
["b"]=>
int(1)
["c"]=>
int(2)
["d"]=>
int(3)
["f"]=>
int(5)
["g"]=>
int(6)
["h"]=>
int(7)
["j"]=>
int(9)
["k"]=>
int(10)
["l"]=>
int(11)
["m"]=>
int(12)
["n"]=>
int(13)
["p"]=>
int(15)
["q"]=>
int(16)
["r"]=>
int(17)
["s"]=>
int(18)
["t"]=>
int(19)
["v"]=>
int(21)
["w"]=>
int(22)
["x"]=>
int(23)
["y"]=>
int(24)
["z"]=>
int(25)
}
If you're using filter_input_array, the values will be null on failure and anything else on success. Because array_filter by default removes false, 0 and "" you need to do extra work like this:
<?php
$input_array = filter_input_array(INPUT_GET, array(
'var1' => FILTER_VALIDATE_BOOLEAN,
'var2' => FILTER_VALIDATE_INT
));
array_filter($input_array, function($a) { return !is_null($a) });
?>
Here's a function that will filter a multi-demensional array. This filter will return only those items that match the $value given
<?php
/*
* filtering an array
*/
function filter_by_value ($array, $index, $value){
if(is_array($array) && count($array)>0)
{
foreach(array_keys($array) as $key){
$temp[$key] = $array[$key][$index];
if ($temp[$key] == $value){
$newarray[$key] = $array[$key];
}
}
}
return $newarray;
}
?>
Example:
<?php
$results = array(
0 => array('key1' => '1', 'key2' => 2, 'key3' => 3),
1 => array('key1' => '12', 'key2' => 22, 'key3' => 32)
);
$nResults = filter_by_value($results, 'key2', '2');
?>
Output :
array(
0 => array('key1' => '1', 'key2' => 2, 'key3' => 3)
);
Here's an easy way to get a combination of keys and values, such that if you don't specify a key you will get the value, and if you do specify a key you will get the key:
<?php
$array = array('One' => 'First', 'Second', 'Third', 'Four' => 'Fourth', 'Fifth');
var_dump(array_keys($array));
$names = array_filter(array_keys($array), 'is_string') + array_values($array);
ksort($array);
var_dump($names);
?>
Outputs:
array(5) {
[0]=>string(3) "One"
[1]=>int(0)
[2]=>int(1)
[3]=>string(4) "Four"
[4]=>int(2)
}
array(5) {
[0]=>string(3) "One"
[1]=>string(6) "Second"
[2]=>string(5) "Third"
[3]=>string(4) "Four"
[4]=>string(5) "Fifth"
}
Without using ksort, the keys appear before the fallback values, instead of inline and appearing like they replace them, however the keys are intact (which is why ksort works) so it's only execution order.
Wanting to pass an additional to parameter to the callback function? This worked for me, there's probably another way to accomplish this task but just so you see how it can be done. (I actually used this technique to strip old dates out of an array) :
<?php
//define in global scope so functions can access
$var_to_pass = null;
function myfilter($input_var_outer,$param) {
global $var_to_pass;
$var_to_pass = $param;
function mycallback($input_var_inner) {
global $var_to_pass;
return ($input_var_inner>$var_to_pass) ? true : false;
}
$return_arr = array_filter($input_var_outer,'mycallback');
//re-key if you want
$return_arr = array_merge(array(),$return_arr);
return $return_arr;
}
$min = 5;
$a = array(1,3,5,7,9);
//remove elements from array that are not greater than $min
$a = myfilter($a,$min);
echo "<pre>";
print_r($a);
echo "</pre>";
?>
--
Output:
Array
(
[0] => 7
[1] => 9
)
I use the following to see if a array consist of scalar values or null, but of course you could mix it up using any of the is_ functions.
<?php
if(count($data) !== count(array_filter($data, 'is_scalar') + array_filter($data, 'is_null'))) {
throw new Exception('Array did not consist of scalar and null values');
}
?>
One of the nice things about this function is that you can a standard php function such as is_string
e.g.
<?php
$input =array(1 , '2', 'three', array('sausages'));
$result = array_filter($input ,'is_string');
print_r($result);
?>
Result will be
Array
(
[1] => 2
[2] => three
)
I wanted a function to keep the values that were filtered out and return them separately. Basically, split the array by some callback. I wrote this for the job:
<?php
function array_split($input, &$trues, &$falses, $compare)
{
while (($item = array_pop($input)) != NULL)
{
if ($compare($item)) $trues[] = $item;
else $falses[] = $item;
}
}
?>
very simple, something I would think would be standard, and array_filter would amount to discarding the falses.
I was looking for a function that could filter values from an array using a regular expression pattern supplied, based on leon at darkk dot net dot ru I created the following:
Description:
Return array of matching values from array using regular expression.
<?php
class array_ereg {
function array_ereg($pattern) { $this->pattern = $pattern; }
function ereg($string) {
return ereg($this->pattern, $string);
}
}
?>
Usage :
<?php
$matches = array_filter($subject, array(new array_ereg($pattern), 'ereg'));
?>
Example:
<?php
$subject = array ("Thumbs.db", "image001.png", "image001.jpg", "image002.png");
print_r(array_filter($subject, array(new array_ereg("image[0-9]{3}\.png"), 'ereg')));
?>
Outputs:
Array ( [1] => image001.png [3] => image002.png )
In case you are interested (like me) in filtering out elements with certain key-names, array_filter won't help you. Instead you can use the following:
<?php
$arr = array( 'element1' => 1, 'element2' => 2, 'element3' => 3, 'element4' => 4 );
$filterOutKeys = array( 'element1', 'element4' );
$filteredArr = array_diff_key( $arr, array_flip( $filterOutKeys ) )
?>
Result will be something like this:
['element2'] => 2
['element3'] => 3
This function filters an array and remove all null values recursively.
<?php
function array_filter_recursive($input)
{
foreach ($input as &$value)
{
if (is_array($value))
{
$value = array_filter_recursive($value);
}
}
return array_filter($input);
}
?>
Or with callback parameter (not tested) :
<?php
function array_filter_recursive($input, $callback = null)
{
foreach ($input as &$value)
{
if (is_array($value))
{
$value = array_filter_recursive($value, $callback);
}
}
return array_filter($input, $callback);
}
?>
Regarding comment about trimming empty strings, the code posted will get into an infinite loop if the array is reduced to zero elements. The following might be better:
<?php
function array_trim($array) {
while (!empty($array) and strlen(reset($array)) === 0) {
array_shift($array);
}
while (!empty($array) and strlen(end($array)) === 0) {
array_pop($array);
}
return $array;
}
?>
Yes, it may remove NULLS, but it also removes anything that factors to a FALSE as well; like FALSE and ZERO. :/
// my implementation for array_filter
function my_array_filter($array,$function,$preserve=true)
{
$return = array();
foreach ($array as $k=>$v)
{
if($function($v)==true) $return[$k]=$v;
}
if($preserve) return $return;
else return array_values($return);
}
function odd($value)
{
return ($value & 1);
}
$oddonly = array (1,2,3,4,5,6,7,8,9);
print_r(my_array_filter($oddonly,'odd',1));
//output
//Array ( [0] => 1 [2] => 3 [4] => 5 [6] => 7 [8] => 9 )
//Khaled Mohammed
You can easily delete all NULL elements from array with following statement:
<?php
$arr = array_filter($arr);
?>
Be careful with this function as it preserves array indexes after applying the filter:
<?php
function f( $item ){
return $item < 50;
}
print_r( array_filter(array( 10, 100, 20 ),"f") );
/* OUTPUT
Array
(
[0] => 10
[2] => 20
)*/
?>
You can easily reassign indexes like this:
<?php
function f( $item ){
return $item < 50;
}
print_r( array_values(array_filter(array( 10, 100, 20 ),"f")) );
/* OUTPUT
Array
(
[0] => 10
[1] => 20
)*/
?>
Don't forget that using callbacks in a class requires that you reference the object name in the callback like so:
<?php
$newArray = array_filter($array, array($this,"callback_function"));
?>
Where "$this" is the reference to your object.
This function trims empty strings from the beginning and end of an array.
It's useful when outputing plaintext files on a page and you want to skip empty lines at the beginning and end, but not within the text.
<?php
function array_trim($array) {
while (strlen(reset($array)) === 0) {
array_shift($array);
}
while (strlen(end($array)) === 0) {
array_pop($array);
}
return $array;
}
?>
You might want to trim each element too.
Just a simplification of my function from last month.
<?php
function partition($input, $callback=null)
{
if(is_null($callback))
$true = array_filter($input);
else
$true = array_filter($input, $callback);
$false = array_diff_key($input, $true);
}
?>
Here is my own version of Renee Sarsoo's array_split() function; given an array and a callback it returns two arrays, in which the first contains elements that passed the filter and the second contains elements that didn't. (If no callback is passed, the first array contains the nonempty elements, as you'd get from array_filter() if you don't give it a callback). Array keys are preserved.
<?php
function partition($input, $callback=null)
{
static $not_empty=null;
if(is_null($not_empty))
$not_empty = create_function('$o', 'return !empty($o);');
if(is_null($callback)) $callback = $not_empty;
$true = array_filter($input, $callback);
$false = array_diff_key($input, $true);
return array($true, $false);
}
?>
Sometimes you want to do something with elements you have filtered out and something else with other elements. So instead of filtering elements out to one array you would like to split array into two parts:
<?php
/**
* Splits array into two arrays using a callback function
*
* It is like array_filter(), but instead of one array, two arrays are returned:
* first one with elements for which the callback function evaluates to true,
* and second one, for which it evaluates to false.
*
* If no callback is supplied, all entries of input equal to FALSE will be removed.
*
* Array keys are preserved.
*
* @param $callback the callback function to use
* @return array(truth_array, false_array)
*/
function array_split($input, $callback=null) {
$callback = isset($callback) ? $callback : create_function('$x', 'return $x == true;');
$true = array();
$false = array();
foreach ($input as $key => $value) {
if (call_user_func($callback, $value)) {
$true[$key] = $value;
}
else {
$false[$key] = $value;
}
}
return array($true, $false);
}
?>
Here is a way to get customizable filter
<?php
function blablabla() {
....
$new = getNewUidls();
class UidlFilter {
function UidlFilter($uidls) { $this->uidls = $uidls; }
function filter($metamsg) { return in_array($metamsg['uidl'], $this->uidls); }
}
$msglist = array_filter($msglist, array(new UidlFilter($new), 'filter');
....
}
?>
As long as the array's keys are irrelevant, there is a simple way to remove blank values from the array, after filtering has been applied. The following example is used to remove all strings from an array that have a length of less than 4 characters.
<?php
function validElement($element) {
return strlen($element) > 3;
}
$filtered_array = array_values(array_filter($input_array, "validElement"));
?>
If you have a form with multiple checkbox having ID element as value for selection in a list, you probably have a SQL request like :
$req="SELECT ... WHERE ID IN (".implode(',', array_keys($choices)).")";
without quote before and after choices keys because they are numeric values... but in fact, they can be string values, and a SQL injection problem.
with array_filter, you can easily filter bad values :
<?php
$choices=array('A'=>'on', -1=>'on', 0=>'on', 1=>'on', 12=>'on', "1)or 1=1--"=>'on');
print_r($choices);
$choices=array_filter(array_keys($choices), 'is_numeric');
print_r($choices);
?>
will print :
<?php
Array
(
[A] => on
[-1] => on
[0] => on
[1] => on
[12] => on
[1)or 1=1--] => on
)
Array
(
[1] => -1
[2] => 0
[3] => 1
[4] => 12
)
?>
I have written a function that will filter an array by the frequency of
element value in the array. This may be useful to some people.
<?php
/////////////////////////////////////////////////////////////////
// Filter an array by value freguebcy
// Input: $array
// cut-off: $frequency (>=1)
// result option option: 1=$frequency and higher
// 0=$frequency only
// -1=$frequency and lower
/////////////////////////////////////////////////////////////////
function filter_array($array, $frequency = 2, $include = 1){
$freg = array_count_values($array);
if($frequency<1){
print "** frequency cut-off should be >= 1! **\n";
return false;
}
foreach($freg as $k => $v){
if($include == 0){
if($frequency != $v){
$freg[$k] = 0;
}
}elseif($include > 0){
if($frequency > $v){
$freg[$k] = 0;
}
}else{
if($frequency < $v){
$freg[$k] = 0;
}
}
}
$filtered = array_filter($freg);
$values = array_keys($filtered);
return array_intersect($array,$values);
}
?>
According to a simple test with array_filter($array) and array_diff($array, array('')) is array_filter 2.5 times faster than array_diff when deleting empty entries.
Some of PHP's array functions play a prominent role in so called functional programming languages, where they show up under a slightly different name:
<?php
array_filter() -> filter(),
array_map() -> map(),
array_reduce() -> foldl() ("fold left")
?>
Functional programming is a paradigm which centers around the side-effect free evaluation of functions. A program execution is a call of a function, which in turn might be defined by many other functions. One idea is to use functions to create special purpose functions from other functions.
The array functions mentioned above allow you compose new functions on arrays.
E.g. array_sum = array_map("sum", $arr).
This leads to a style of programming that looks much like algebra, e.g. the Bird/Meertens formalism.
E.g. a mathematician might state
map(f o g) = map(f) o map(g)
the so called "loop fusion" law.
Many functions on arrays can be created by the use of the foldr() function (which works like foldl, but eating up array elements from the right).
I can't get into detail here, I just wanted to provide a hint about where this stuff also shows up and the theory behind it.
For any type of array. Basead in redshift code.
<?php
function array_clean ($array, $todelete = false, $caseSensitive = false) {
foreach($array as $key => $value) {
if(is_array($value)) {
$array[$key] = array_clean($array[$key], $todelete, $caseSensitive);
}
else {
if($todelete) {
if($caseSensitive) {
if(strstr($value ,$todelete) !== false)
unset($array[$key]);
}
else {
if(stristr($value, $todelete) !== false)
unset($array[$key]);
}
}
elseif (empty($value)) {
unset($array[$key]);
}
}
}
return $array;
}
?>
The anonymous fellow a few posts up was trying to illustrate how to use the array_filter() function with class methods but confused things a bit. Here's a cleaner example:
<?php
class testclass
{
function testclass()
{
// define the numbers array
$numbers = array(1, 2, 3, 4, 5, 6);
// pull out the odd numbers
$odd = array_filter($numbers, array($this, "odd"));
// pull out the even numbers
$even = array_filter($numbers, array($this, "even"));
}
function odd($var)
{
return($var % 2 == 1);
}
function even($var)
{
return($var % 2 == 0);
}
}
?>
Here is a nice little function which will apply a callback function recursively over a multidimensional array. If the callback function returns false, then it replaces the value of the array with $filtered_ouput. This function gracefully handles objects inside of arrays (and objects within objects within arrays, etc). It is specifically designed for your callback function to process on the array key's (unlike normal array_filter which filters on the values), but it could work on the array values depending on your test criteria (YMMV).
<?PHP
function array_key_filter_multi($array, $callback, $filtered_output = "")
{
$ret = array();
foreach($array as $key=>$value) {
if($callback($key,$value)) {
if(is_array($value)) {
$ret[$key] = array_key_filter_multi($value, $callback, $filtered_output);
}
elseif(is_object($value)) {
$ret[$key] = array_key_filter_multi(get_object_vars($value), $callback, $filtered_output);
}
else {
$ret[$key]=$value;
}
}
else {
$ret[$key]=$filtered_output;
}
}
return $ret;
}
?>
We use this to filter redundant data from debugging output. An example usage is:
<?
$callback_func = create_function('$key, $value', 'return ($key == "db" || $key == "smarty") ? false : true;');
echo "<PRE>" . print_r(array_key_filter_multi($_SESSION, $callback_func, "**filtered by function**"), true) . "</PRE>";
?>
Which filters all keys with "db" or "smarty" as their name (including objects which have a reference to those variables). The output of the above in a test case I did is the following:
Array
(
[userdata] => Array
(
[sid] => a130e675d380e0e9fe47897922d719ac
[not_in_db] =>
[user_id] => 1
[session_id] => 154
[permissions] => 1
[username] => tester
)
[systemobjects] => Array
(
[db] => **filtered by function**
[smarty] => **filtered by function**
)
)
Hi all,
Here's a function that will look trough an array, and removes the array member when the search string is found.
<?php
function array_clean ($input, $delete = false, $caseSensitive = false)
{
$i = 0;
while($i < count($input))
{
if($delete)
{
if($caseSensitive)
{
if(!strstr($input[$i] ,$delete))
{
$return[] = $input[$i];
}
}
else
{
if(!stristr($input[$i], $delete))
{
$return[] = $input[$i];
}
}
}
else
{
if(!empty($input[$i]))
{
$return[] = $input[$i];
}
}
$i++;
}
return $return;
}
?>
array array_clean(array input [, string needle [, boolean case sensitive]])
if needle is left empty, the function will delete the array members that have no value (this means if it's empty).
NOTE: It rebuilds the array from scratch, so keys begin with 0, like you would create a new array.
Example:
$array = array("John", "Doe", "Macy");
$array = array_clean($array, "doe", false);
print_r($array);
would return:
array
(
[0] => John
[1] => Macy
)
Hopes this helps someone :-)
The following function modifies the supplied array recursively so that filtering is performed on multidimentional arrays as well, while preserving keys.
<?php
function array_cleanse(&$arr){
$temp = array();
reset($arr);
if(count($arr) == 0) return "";
foreach($arr as $key=>$val):
(is_array($val))? array_cleanse($val) : NULL;
($val)? $temp[$key] = $val : NULL;
endforeach;
$arr = $temp;
reset($arr);
}
?>
$arr1 = array('a'=>20,'b'=>array(''),'c'=>array(1,0,2),'d'=>0);
array_cleanse($arr1);
$arr1 will be array('a'=>20,'c'=>array(1,2))
array_filter may not be used as it does not modify the array within itself.
You cannot do this:
$non_empty_array = array_filter($original_array, 'empty');
Since empty() is not a function but a language construct. (http://www.php.net/manual/en/function.empty.php)
be careful with the above function "array_delete"'s use of the stristr function, it could be slightly misleading. consider the following:
<?php
function array_delete($array, $filterforsubstring){
$thisarray = array ();
foreach($array as $value)
if(stristr($value, $filterforsubstring)===false && strlen($value)>0)
$thisarray[] = $value;
return $thisarray;
}
function array_delete2($array, $filterforstring, $removeblanksflag=0){
$thisarray = array ();
foreach($array as $value)
if(!(stristr($value, $filterforstring) && strlen($value)==strlen($filterforstring))
&& !(strlen($value)==0 && $removeblanksflag))
$thisarray[] = $value;
return $thisarray;
}
function array_delete3($array, $filterfor, $substringflag=0, $removeblanksflag=0){
$thisarray = array ();
foreach($array as $value)
if(
!(stristr($value, $filterfor)
&& ($substringflag || strlen($value)==strlen($filterfor))
)
&& !(strlen($value)==0 && $removeblanksflag)
)
$thisarray[] = $value;
return $thisarray;
}
$array1 = array ('the OtHeR thang','this', 'that', 'OtHer','', 9, 101, 'fifty', ' oTher', 'otHer ','','other','Other','','other blank things');
echo "<pre>array :\n";
print_r($array1);
$array2=array_delete($array1, "Other");
echo "array_delete(\$array1, \"Other\"):\n";
print_r($array2);
$array2=array_delete2($array1, "Other");
echo "array_delete2(\$array1, \"Other\"):\n";
print_r($array2);
$array2=array_delete2($array1, "Other",1);
echo "array_delete2(\$array1, \"Other\",1):\n";
print_r($array2);
$array2=array_delete3($array1, "Other",1);
echo "array_delete3(\$array1, \"Other\",1):\n";
print_r($array2);
$array2=array_delete3($array1, "Other",0,1);
echo "array_delete3(\$array1, \"Other\",0,1):\n";
print_r($array2);
?>
I was looking for a function to delete values from an array and thought I had found it in array_filter(), however, I *didn't* want the keys to be preserved *and* I needed blank values cleaned out of the array as well. I came up with the following (with help from many of the above examples):
<?php
function array_delete($array, $filterfor){
$thisarray = array ();
foreach($array as $value)
if(stristr($value, $filterfor)===false && strlen($value)>0)
$thisarray[] = $value;
return $thisarray;
}
$array1 = array ('OtHeR','this', 'that', 'Other','', 9, 101, 'fifty', 'other','','');
echo "<pre>array :\n";
print_r($array1);
$array2=array_delete($array1, "Other");
echo "filtered:\n";
print_r($array2);
?>
I was looking for a function able to take some values out of an array iteratively, and found array_filter very useful although i had some trouble figuring out the proper syntax...
<?php
class someclass {
var $current;
/** this is our iterative function */
function main ($variable,$array){
if (end test){
return true;
}
$variable= some treatment...
if (in_array($variable, $array)){
$this->current=something...($variable);
// this is the not-well-documented part
$array=$array_filter($array, array($this, "array_reduce");
}
$this->main($variable, $array);
}
/** this is the function used to filter */
function reduce_list($var){
return ($var!=$this->current);
}
}
?>
Here's a good function to filter multidimensional arrays:
<?php
function array_filter_multi($input, $filter="", $keepMatches=true) {
if (!is_array($input))
return ($input==$filter xor $keepMatches==false) ? $input : false;
while (list ($key,$value) = @each($input)){
$res = array_filter_multi($value, $filter,$keepMatches);
if ($res !== false)
$out[$key] = $res;
}
return $out;
}
?>
Default behavior is to remove blanks from a multi-dimensional array, but you can filter out any string (arg #2) with a positive or negative filter (arg #3).
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