Array slice function that works with associative arrays (keys):
function array_slice_assoc($array,$keys) {
return array_intersect_key($array,array_flip($keys));
}
(PHP 4, PHP 5, PHP 7, PHP 8)
array_slice — Extraer una parte de un array
array_slice() devuelve la secuencia de elementos
del array array
tal y como se especifica en
los parámetros offset
y
length
.
array
El array de entrada.
offset
Si el índice dado por offset
no es negativo, la secuencia
empezará en esa posición del array
. Si el
offset
es negativo, la secuencia
empezará en esa posición empezando por el final del array
.
length
Si la longitud dada por length
es positiva,
la secuencia tendrá hasta tantos elementos como indique el valor. Si el array
es más corto que length
, solamente estarán
presentes los elementos disponibles del array. Si se proporciona
length
y es negativo, la
secuencia finalizará en tantos elementos empezando por el final del
array. Si se omite, entonces la secuencia contendrá todo el contenido
desde offset
hasta el final del
array
.
preserve_keys
Observe que array_slice() reordenará y reinicializará los
índices numéricos del array de forma predeterminada. Se puede cambiar esta comportamiento
estableciendo el parámetro preserve_keys
a true
.
Devuelve la parte del array. Si el índice es mayor que el tamaño del array, devuelve un array vacío.
Versión | Descripción |
---|---|
5.2.4 |
El valor predeterminado del parámetro length se cambió a NULL . Una length NULL ahora indica a la función que use la longitud de array . Antes de esta versión, una length NULL se tomaba como de longitud cero (no se devolvía nada).
|
5.0.2 |
Se añadió el parámetro opcional preserve_keys .
|
Ejemplo #1 Ejemplos de array_slice()
<?php
$entrada = array("a", "b", "c", "d", "e");
$salida = array_slice($entrada, 2); // devuelve "c", "d", y "e"
$salida = array_slice($entrada, -2, 1); // devuelve "d"
$salida = array_slice($entrada, 0, 3); // devuelve "a", "b", y "c"
// observe las diferencias en las claves de los arrays
print_r(array_slice($entrada, 2, -1));
print_r(array_slice($entrada, 2, -1, true));
?>
El resultado del ejemplo sería:
Array ( [0] => c [1] => d ) Array ( [2] => c [3] => d )
Array slice function that works with associative arrays (keys):
function array_slice_assoc($array,$keys) {
return array_intersect_key($array,array_flip($keys));
}
If you want an associative version of this you can do the following:
function array_slice_assoc($array,$keys) {
return array_intersect_key($array,array_flip($keys));
}
However, if you want an inverse associative version of this, just use array_diff_key instead of array_intersect_key.
function array_slice_assoc_inverse($array,$keys) {
return array_diff_key($array,array_flip($keys));
}
Example:
$arr = [
'name' => 'Nathan',
'age' => 20,
'height' => 6
];
array_slice_assoc($arr, ['name','age']);
will return
Array (
'name' = 'Nathan',
'age' = 20
)
Where as
array_slice_assoc_inverse($arr, ['name']);
will return
Array (
'age' = 20,
'height' = 6
)
<?php
// CHOP $num ELEMENTS OFF THE FRONT OF AN ARRAY
// RETURN THE CHOP, SHORTENING THE SUBJECT ARRAY
function array_chop(&$arr, $num)
{
$ret = array_slice($arr, 0, $num);
$arr = array_slice($arr, $num);
return $ret;
}
based on worldclimb's arem(), here is a recursive array value removal tool that can work with multidimensional arrays.
function remove_from_array($array,$value){
$clear = true;
$holding=array();
foreach($array as $k => $v){
if (is_array($v)) {
$holding [$k] = remove_from_array ($v, $value);
}
elseif ($value == $v) {
$clear = false;
}
elseif($value != $v){
$holding[$k]=$v; // removes an item by combing through the array in order and saving the good stuff
}
}
if ($clear) return $holding; // only pass back the holding array if we didn't find the value
}
array_slice can be used to remove elements from an array but it's pretty simple to use a custom function.
One day array_remove() might become part of PHP and will likely be a reserved function name, hence the unobvious choice for this function's names.
<?
function arem($array,$value){
$holding=array();
foreach($array as $k => $v){
if($value!=$v){
$holding[$k]=$v;
}
}
return $holding;
}
function akrem($array,$key){
$holding=array();
foreach($array as $k => $v){
if($key!=$k){
$holding[$k]=$v;
}
}
return $holding;
}
$lunch = array('sandwich' => 'cheese', 'cookie'=>'oatmeal','drink' => 'tea','fruit' => 'apple');
echo '<pre>';
print_r($lunch);
$lunch=arem($lunch,'apple');
print_r($lunch);
$lunch=akrem($lunch,'sandwich');
print_r($lunch);
echo '</pre>';
?>
(remove 9's in email)
remember that array_slice returns an array with the current element. you must use array_slice($array, $index+1) if you want to get the next elements.
Using the varname function referenced from the array_search page, submitted by dcez at land dot ru. I created a multi-dimensional array splice function. It's usage is like so:
$array['admin'] = array('blah1', 'blah2');
$array['voice'] = array('blah3', 'blah4');
array_cut('blah4', $array);
...Would strip blah4 from the array, no matter where the position of it was in the array ^^ Returning this...
Array ( [admin] => Array ( [0] => blah1 [1] => blah2 ) [voice] => Array ( [0] => blah3 ) )
Here is the code...
<?php
function varname ($var)
{
// varname function by dcez at land dot ru
return (isset($var)) ? array_search($var, $GLOBALS) : false;
}
function array_cut($needle, $haystack)
{
foreach ($haystack as $k => $v)
{
for ($i=0; $i<count($v); $i++)
if ($v[$i] === $needle)
{
return array_splice($GLOBALS[varname($haystack)][$k], $i, 1);
break; break;
}
}
?>
Check out dreamevilconcept's forum for more innovative creations!
The documentation doesn't say it, but if LENGTH is ZERO, then the result is an empty array [].
To save the sort order of a numeric index in the array. Version php =>5.5.26
/*
Example
*/
$arr = array( "1" =>2, "2" =>3 , "3" =>5 );
print_r(array_slice($arr,1,null,true));
/*
Result
Array
(
[2] => 3
[3] => 5
)
*/
<?php
// Combines two arrays by inserting one into the other at a given position then returns the result
function array_insert($src, $dest, $pos) {
if (!is_array($src) || !is_array($dest) || $pos <= 0) return FALSE;
return array_merge(array_slice($dest, 0, $pos), $src, array_slice($dest, $pos));
}
?>
If you specify the fourth argument (to not reassign the keys), then there appears to be no way to get the function to return all values to the end of the array. Assigning -0 or NULL or just putting two commas in a row won't return any results.
<?php
/**
* Reorders an array by keys according to a list of values.
* @param array $array the array to reorder. Passed by reference
* @param array $list the list to reorder by
* @param boolean $keepRest if set to FALSE, anything not in the $list array will be removed.
* @param boolean $prepend if set to TRUE, will prepend the remaining values instead of appending them
* @author xananax AT yelostudio DOT com
*/
function array_reorder(array &$array,array $list,$keepRest=TRUE,$prepend=FALSE,$preserveKeys=TRUE){
$temp = array();
foreach($list as $i){
if(isset($array[$i])){
$tempValue = array_slice(
$array,
array_search($i,array_keys($array)),
1,
$preserveKeys
);
$temp[$i] = array_shift($tempValue);
unset($array[$i]);
}
}
$array = $keepRest ?
($prepend?
$array+$temp
:$temp+$array
)
: $temp;
}
/** exemple ** /
$a = array(
'a' => 'a',
'b' => 'b',
'c' => 'c',
'd' => 'd',
'e' => 'e'
);
$order = array('c','b','a');
array_reorder($a,$order,TRUE);
echo '<pre>';
print_r($a);
echo '</pre>';
/** exemple end **/
?>
/**
* Remove a value from a array
* @param string $val
* @param array $arr
* @return array $array_remval
*/
function array_remval($val, &$arr)
{
$array_remval = $arr;
for($x=0;$x<count($array_remval);$x++)
{
$i=array_search($val,$array_remval);
if (is_numeric($i)) {
$array_temp = array_slice($array_remval, 0, $i );
$array_temp2 = array_slice($array_remval, $i+1, count($array_remval)-1 );
$array_remval = array_merge($array_temp, $array_temp2);
}
}
return $array_remval;
}
$stack=Array('apple','banana','pear','apple', 'cherry', 'apple');
array_remval("apple", $stack);
//output: Array('banana','pear', 'cherry')
Note that offset is not the same thing as key. Offset always starts at 0, while keys might be any number.
So this:
<?php print_r(array_slice(array(0 => 0, 5 => 5, 13 => 13),1)); ?>
will result in this:
Array
(
[0] => 5
[1] => 13
)
<?php
/**
* @desc
* Combines two arrays by inserting one into the other at a given position then
* returns the result.
*
* @since 2007/10/04
* @version v0.7 2007/10/04 18:47:52
* @author AexChecker <AexChecker@yahoo.com>
* @param array $source
* @param array $destination
* @param int [optional] $offset
* @param int [optional] $length
* @return array
*/
function array_insert($source, $destination, $offset = NULL, $length = NULL) {
if (!is_array($source) || empty($source)) {
if (is_array($destination) && !empty($destination)) {
return $destination;
}
return array();
}
if (is_null($offset)) {
return array_merge($destination, $source);
}
$offset = var2int($offset);
if (is_null($length)) {
if ($offset === 0) {
return array_merge($source, array_slice($destination, 1));
}
if ($offset === -1) {
return array_merge(array_slice($destination, 0, -1), $source);
}
return array_merge(
array_slice($destination, 0, $offset),
$source,
array_slice($destination, ++$offset)
);
}
if ($offset === 0) {
return array_merge($source, array_slice($destination, $length));
}
$destination_count = count($destination);
$length = var2int($length);
if ($offset > 0) {
if ($destination_count - $offset < 1) {
return array_merge($destination, $source);
}
} else{
if (($t = $destination_count + $offset) < 1) {
return array_merge($source, $destination);
}
$offset = $t;
}
if ($length > 0) {
$length+= $offset;
} elseif ($length < 0 && !($length * -1 < $destination_count)) {
return $source;
} else {
$length = $offset;
}
return array_merge(
array_slice($destination, 0, $offset),
$source,
array_slice($destination, $length)
);
}
?>
Sometimes you need to pick certain non-integer and/or non-sequential keys out of an array. Consider using the array_pick() implementation below to pull specific keys, in a specific order, out of a source array:
<?php
$a = array ('a' => 1, 'b' => 2, 'c' => 3, 'd' => 4);
$b = array_pick($a, array ('d', 'b'));
// now:
// $a = array ('a' => 1, 'c' => '3');
// $b = array ('d' => 4, 'b' => '2');
function &array_pick(&$array, $keys)
{
if (! is_array($array)) {
trigger_error('First parameter must be an array', E_USER_ERROR);
return false;
}
if (! (is_array($keys) || is_scalar($keys))) {
trigger_error('Second parameter must be an array of keys or a scalar key', E_USER_ERROR);
return false;
}
if (is_array($keys)) {
// nothing to do
} else if (is_scalar($keys)) {
$keys = array ($keys);
}
$resultArray = array ();
foreach ($keys as $key) {
if (is_scalar($key)) {
if (array_key_exists($key, $array)) {
$resultArray[$key] = $array[$key];
unset($array[$key]);
}
} else {
trigger_error('Supplied key is not scalar', E_USER_ERROR);
return false;
}
}
return $resultArray;
}
?>