Notice:
the complexity of array_pop() is O(1).
the complexity of array_shift() is O(n).
array_shift() requires a re-index process on the array, so it has to run over all the elements and index them.
array_pop
(PHP 4, PHP 5, PHP 7)
array_pop — Pop the element off the end of array
Description
array_pop() pops and returns the value of
the last element of array, shortening the
array by one element.
Note: This function will reset() the array pointer of the input array after use.
Parameters
-
array -
The array to get the value from.
Return Values
Returns the value of the last element of array.
If array is empty (or is not an array),
NULL will be returned.
Errors/Exceptions
This function will produce an error of level E_WARNING when called on a non-array.
Examples
Example #1 array_pop() example
<?php
$stack = array("orange", "banana", "apple", "raspberry");
$fruit = array_pop($stack);
print_r($stack);
?>
After this, $stack will have only 3 elements:
Array
(
[0] => orange
[1] => banana
[2] => apple
)
and raspberry will be assigned to $fruit.
See Also
- array_push() - Push one or more elements onto the end of array
- array_shift() - Shift an element off the beginning of array
- array_unshift() - Prepend one or more elements to the beginning of an array
add a note
User Contributed Notes 15 notes
elad dot yosifon at gmail dot com ¶
6 years ago
mcgroovin at gmail dot com ¶
10 years ago
I wrote a simple function to perform an intersect on multiple (unlimited) arrays.
Pass an array containing all the arrays you want to compare, along with what key to match by.
<?php
function multipleArrayIntersect($arrayOfArrays, $matchKey)
{
$compareArray = array_pop($arrayOfArrays);
foreach($compareArray AS $key => $valueArray){
foreach($arrayOfArrays AS $subArray => $contents){
if (!in_array($compareArray[$key][$matchKey], $contents)){
unset($compareArray[$key]);
}
}
}
return $compareArray;
}
?>
doyley3731 at gmail dot com ¶
11 years ago
I had a problem when using this function because my array was made up entirley of numbers, so I have made my own function. Hopefully it will be useful to somebody.
function array_trim_end($array){
$num=count($array);
$num=$num-1;
unset($array[$num]);
return $array;
}
rmondragon at gmail dot com ¶
14 years ago
In a previous example ...
<?php
function array_trim ( $array, $index ) {
if ( is_array ( $array ) ) {
unset ( $array[$index] );
array_unshift ( $array, array_shift ( $array ) );
return $array;
}
else {
return false;
}
}
?>
This have a problem. if u unset the last value and then use
<?
array_unshift ( $array, array_shift ( $array ) );
?>
will return a : Array ( [0] => )
so u can fix it using...
<?php
if (count($array) > 0) array_unshift ( $values, array_shift ( $values ) );
?>
good luck ;)
Anonymous ¶
14 years ago
strrchr is a lot more useful than the other example using array_pop for finding the extension of a file. For example:
<?php
$ext = strrchr($filename, ".");
?>
$ext will contain the extension of the file, including a ".", if the file has an extension, and FALSE if the file has no extension. If the file has multiple extensions, such as "filename.tar.gz", then this construction will just return the last extension.
Anonymous ¶
5 years ago
Strict Standards will be thrown out if you put exploded array in array_pop:
<?php
$a = array_pop(explode(",", "a,b,c"));
echo $a;
?>
You will see:
PHP Strict Standards: Only variables should be passed by reference in - on line 2
Strict Standards: Only variables should be passed by reference in - on line 2
c
Notice that, you should assign a variable for function explode, then pass the variable reference into array_pop to avoid the Strict Standard warning.
qeremy ¶
7 years ago
For the sake of array_unshift()
:)
<?php
function array_unpop(&$arr) {
$args = func_get_args(); unset($args[0]);
$tarr = array();
foreach ($args as $arg) {
$tarr[] = $arg;
}
$arr = array_merge($arr, $tarr);
}
$queue = array("orange", "banana");
array_unpop($queue, "apple", "raspberry");
print_r($queue);
?>
Array
(
[0] => orange
[1] => banana
[2] => apple
[3] => raspberry
)
Orsi ¶
11 years ago
Hi,
Here is a simple function which delete one element from the array (with value):
<?php
/*
* This function deletes the given element from a one-dimension array
* Parameters: $array: the array (in/out)
* $deleteIt: the value which we would like to delete
* $useOldKeys: if it is false then the function will re-index the array (from 0, 1, ...)
* if it is true: the function will keep the old keys
* Returns true, if this value was in the array, otherwise false (in this case the array is same as before)
*/
function deleteFromArray(&$array, $deleteIt, $useOldKeys = FALSE)
{
$tmpArray = array();
$found = FALSE;
foreach($array as $key => $value)
{
if($value !== $deleteIt)
{
if(FALSE === $useOldKeys)
{
$tmpArray[] = $value;
}
else
{
$tmpArray[$key] = $value;
}
}
else
{
$found = TRUE;
}
}
$array = $tmpArray;
return $found;
}
?>
Maybe it will help somebody...
eddie at metafoundry dot com ¶
14 years ago
Quick way to get the extension from a file name using array_pop:
$ext = array_pop(explode(".",$filename));
¶
16 years ago
alex.chacon@terra.com
Hi
Here there is a function that delete a elemente from a array and re calculate indexes
<?php
function eliminarElementoArreglo ($array, $indice)
{
if (array_key_exists($indice, $array))
{
$temp = $array[0];
$array[0] = $array[$indice];
$array[$indice] = $temp;
array_shift($array);
//reacomodamos índices
for ($i = 0 ; $i < $indice ; $i++)
{
$dummy = $array[$i];
$array[$i] = $temp;
$temp = $dummy;
}
}
return $array;
}
?>
sonetti at hotmail dot com ¶
11 years ago
@smp_info
I think you are still tired. What would be wrong with:
<?php
$array = array('one', 'two', 'three', 'four');
//pop the last element off
array_pop($array);
//$array == array('one', 'two', 'three');
?>
As the documentation clearly notes, array_pop() not only returns the last element, but actually removes it from the array wich is passed by reference. Calling array_diff is a waste of resources.
Anonymous ¶
15 years ago
A function to delete an array value that recalculates the index ( its very short and easy to understand ).
Hope this might help someone...
<?php
/* Usage:
$array : Array
$indey : Integer
The value of $array at the index $index will be
deleted by the function.
*/
function array_trim ( $array, $index ) {
if ( is_array ( $array ) ) {
unset ( $array[$index] );
array_unshift ( $array, array_shift ( $array ) );
return $array;
}
else {
return false;
}
}
?>
Igor Feghali ¶
10 years ago
Beware that array_pop() returns a copy of the element (even if the array element is a reference). That means you will get different results on PHP 4 and 5 when dealing with objects.
<?php
$a = new stdClass();
$a->foo = 'bar';
$arr = array(&$a);
$b = array_pop($arr);
$b->foo = 'baz';
var_dump($a);
?>
Output of PHP 5.2.8:
object(stdClass)#1 (1) {
["foo"]=>
string(3) "baz"
}
Output of PHP 4.4.9:
object(stdClass)(1) {
["foo"]=>
string(3) "bar"
}
For more information please refer to:
http://br2.php.net/manual/en/language.oop5.references.php
ryan8613(at)hotmail(dot)com ¶
16 years ago
A function that may help some out, considering it's pretty much the one mentioned previously...
<?php
function array_trim($arr, $indice) {
if(!isset($indice)) {
$indice = count($arr)-1;
}
unset($arr[$indice]);
array_shift($arr);
return $arr;
}
?>
It cuts the given index value off of the array, but without the shift, if the 'index' value isn't given, it cuts off the end value.
Anonymous ¶
3 years ago
Let's "do stuff" with array_pop()
<?php
$dependecyInjection = ['globalState' => 'isHorrible'];
$workQueue = array_reverse($workQueue); // O(n)
// While we have stuff to do..... = [[ {function}, $params.... ], [], []...]
while (!empty($workQueue)) {
// O(1) : And resize array. (maybe also memory size ?)
$work = array_pop($workQueue);
// If not `muted`, invoke the worker function....
if (isset($work[0])) {
$processor = array_shift($work);
if ($moreWork = $processor->__invoke($work, $dependecyInjection)) { // <== Do stuff.
// O(n) : add new stuff to the END of array ! (FIFO)
$outputCommands += array_reverse($moreWork);
}
}
}
