array_pop

(PHP 4, PHP 5, PHP 7)

array_pop — Pop the element off the end of array

Description

mixed array_pop ( array &$array )

array_pop() pops and returns the last value of the 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 last value 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.

User Contributed Notes

mcgroovin at gmail dot com

7 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;

}

?>

elad dot yosifon at gmail dot com

2 years ago


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.

rmondragon at gmail dot com

10 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 ;)

doyley3731 at gmail dot com

8 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;
}

ryan8613(at)hotmail(dot)com

12 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

11 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.

qeremy

4 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
)

sonetti at hotmail dot com

8 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.

Orsi

8 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...

Anonymous

2 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.

13 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 �ndices

        for ($i = 0 ; $i < $indice ; $i++)

        {

            $dummy = $array[$i];

            $array[$i] = $temp;

            $temp = $dummy;

        }

    }

    return $array;

}

?>

Anonymous

5 months 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);
    }
  }
}

eddie at metafoundry dot com

11 years ago


Quick way to get the extension from a file name using array_pop:

$ext = array_pop(explode(".",$filename));

Anonymous

12 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

7 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

array_pop

Description

Parameters

Return Values

Errors/Exceptions

Examples

See Also

User Contributed Notes