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(PHP 4, PHP 5)
array_pop — Liefert das letzte Element eines Arrays
array_pop() liefert den letzten Wert von array, und verkürzt array um ein Element. Ist array leer (oder kein Array), wird NULL zurückgegeben. In letzterem Fall wird auch eine Warnung erzeugt.
Hinweis: Diese Funktion setzt (reset()) nach Verwendung den array-Zeiger zurück.
Das Array, aus dem der Wert geholt werden soll.
Gibt den letzten Wert von array zurück. Wenn array leer ist (oder kein Array), wird NULL zurückgegeben.
Beispiel #1 array_pop()-Beispiel
<?php
$stack = array("Orange", "Banane", "Apfel", "Himbeere");
$fruit = array_pop($stack);
print_r($stack);
?>
Danach hat $stack nur 3 Elemente:
Array
(
[0] => Orange
[1] => Banane
[2] => Apfel
)
und Himbeere wird $fruit zugewiesen.
to apply arra_pop serveral times but not recursive
<?php
function array_mpop($array, $iterate)
{
if(!is_array($array) && is_int($iterate))
return false;
while(($iterate--)!=false)
array_pop($array);
return $array;
}
?>
for test :
<?php
$a = array("titi", "toto", "tata", "tonton", "toutou", "tutu");
$a = array_mpop($a, 2);
var_dump($a);
?>
result :
array(4) { [0]=> string(4) "titi" [1]=> string(4) "toto" [2]=> string(4) "tata" [3]=> string(6) "tonton" }
Regarding the last few comments.
To delete the first item in an array:
<?php
array_shift($array);
?>
To get the filename or the file's mtime:
<?php
$filename = basename(__FILE__);
$mod = filemtime(__FILE__);
?>
Want to delete the first element in an array? Here's a small and handy function that'll do the trick!
function array_pop_first(&$array) {
$array = array_reverse($array);
array_pop($array);
$array = array_reverse($array);
}
@Jochen
You could use PHP's pathinfo function to achieve the same results:
<?php
$mod = filemtime(pathinfo($_SERVER['PHP_SELF'], PATHINFO_FILENAME));
?>
I have used array_pop() in a function that returns the name of the current file. This can be used, for example, in conjunction with filemtime() to get the modification time of the current file. The function I coded is a one-liner:
<?php
function whoAmI(){
return array_pop(explode("/", $_SERVER['PHP_SELF']));
}
?>
If your file URI is www.example.com/bar/foobar.php, whoAmI() will return foobar.php. To use it with e.g. filemtime() you would simply write:
<?php
$modtime = filemtime(whoAmI());
?>
Greetings,
Jochen
2 line changes to my previous submission:
$theJumpNumber = (round(count($temparray)/2) + $startingFileNumber) % count($temparray); // use of startingfilenumber randomizes the jump number
while (count($temparray) % $theJumpNumber == 0
|| !isPrime($theJumpNumber)) // !isPrime as easy way to check for no cofactors
You need to check for no cofactors so you can cycle round the complete array without duplicates. Checking !isPrime on theJumpNumber is a pretty easy way to do that. isPrime can be found by google: php isprime
As already mentioned, array_pop always returns a copy, never a reference, which can be a problem in some cases.
Here is a pop function that allows you to get the reference.
(keep in mind it will alter the internal pointer of the array)
<?php
function &array_rpop(&$a){
end($a);
$k=key($a);
$v=&$a[$k];
unset($a[$k]);
return $v;
}
// try this:
$A='A';
$B=array(&$A);
//$C=&array_rpop($B); // will work
$C=&array_pop($B); // won't work
$C='C';
var_dump($A,$B,$C);
?>
I hope the PHP people will make the regular function work with references.
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
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;
}
?>
@Orsi
correct me if I'm wrong... but an easier version might be
<?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)
{
$key = array_search($deleteIt,$array,TRUE);
if($key === FALSE)
return FALSE;
unset($array[$key]);
if(!$useOldKeys)
$array = array_values($array);
return TRUE;
}
?>
--untested but should work.. rite?--
@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.
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...
I'm sorry, I must have been extremely tired when writing the note below. :P
Replace $element with $array, and the code will work nicely.
The right code would be..
<?php
//$array = array('one', 'two', 'three', 'four');
//pop the last element off and return the array
$array = array_diff($array, array(array_pop($array)));
//$array = array('one', 'two', 'three');
I've found myself several times wanting the array (minus the popped element) returned, instead of the element returned.
The following code does this nicely:
<?php
//$array = array('one', 'two', 'three', 'four');
//pop the last element off and return the array
$array = array_diff($array, array(array_pop($element)));
//$array = array('one', 'two', 'three');
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.
Quick way to get the extension from a file name using array_pop:
$ext = array_pop(explode(".",$filename));
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;
}
}
?>
array_pop() can be usefull for fetching extentions of files, especially in cases where there might be more than one period in the filename.
eg:
<?php
$filename = "textfile.txt.bak";
$tmp = explode(".", $filename);
$ext = array_pop($tmp);
print_r($ext); // Shows "bak"
?>
Be aware that using array_pop on an associative array that uses a numeric string as a key changes the key:
<?php
$stack= array("12" => "green", "54" => "brown", "672" => "blue");
print_r($stack);
$fruit = array_pop($stack);
print_r($stack);
?>
Results of execution:
Array
(
[12] => green
[54] => brown
[672] => blue
)
Array
(
[0] => green
[1] => brown
)
However, if there is a non-numeric character in the key, the key will be maintained:
<?php
$stack= array("g1" => "green", "b1" => "brown", "b2" => "blue");
print_r($stack);
$fruit = array_pop($stack);
print_r($stack);
?>
Results of execution:
Array
(
[g1] => green
[b1] => brown
[b2] => blue
)
Array
(
[g1] => green
[b1] => brown
)
A function that may help some out, considering it's pretty much the one mentioned previously...
<?php
function array_trim($arr, $indice) {
if(!isset($indice)) {
$indice = count($arr)-1;
}
unset($arr[$indice]);
array_shift($arr);
return $arr;
}
?>
It cuts the given index value off of the array, but without the shift, if the 'index' value isn't given, it cuts off the end value.
alex.chacon@terra.com
Hi
Here there is a function that delete a elemente from a array and re calculate indexes
<?php
function eliminarElementoArreglo ($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;
}
?>
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