array_pop()

(PHP 4, PHP 5, PHP 7)

弹出数组最后一个单元（出栈）

说明

array_pop(array &$array): mixed

array_pop()弹出并返回$array数组的最后一个单元，并将数组$array的长度减一。

Note:使用此函数后会重置（reset()）array指针。

参数

$array

需要弹出栈的数组。

返回值

返回$array的最后一个值。如果$array是空（如果不是一个数组），将会返回NULL。

错误／异常

调用此函数去处理非数组的值，会产生E_WARNING级别的错误。

范例

Example #1array_pop()例子

<?php
$stack = array("orange", "banana", "apple", "raspberry");
$fruit = array_pop($stack);
print_r($stack);
?>

经过此操作后，$stack将只有 3 个单元：

Array
(
    [0] => orange
    [1] => banana
    [2] => apple
)

并且raspberry将被赋给$fruit。

参见

• array_push() 将一个或多个单元压入数组的末尾（入栈）
• array_shift() 将数组开头的单元移出数组
• array_unshift() 在数组开头插入一个或多个单元

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.

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;
}
?>

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;
}

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 ;)

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.

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.

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
)

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...

Quick way to get the extension from a file name using array_pop:
$ext = array_pop(explode(".",$filename));

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;
}
?>

@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.

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;
   }
  }
?>

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

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.

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);
  }
 }
}