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array_push

(PHP 4, PHP 5, PHP 7)

array_push — 将一个或多个单元压入数组的末尾（入栈）

说明

int array_push ( array &$array , mixed $var [, mixed $... ] )

array_push() 将 array 当成一个栈，并将传入的变量压入 array 的末尾。array 的长度将根据入栈变量的数目增加。和如下效果相同：

  <?php
$array [] =  $var ;
 ?>

并对每个 var 重复以上动作。

Note: 如果用 array_push() 来给数组增加一个单元，还不如用 $array[] = ，因为这样没有调用函数的额外负担。

Note: 如果第一个参数不是数组， array_push() 将发出一条警告。这和 $var[] 的行为不同，后者会新建一个数组。

参数

array: 输入的数组。
var: 要压入的值。

返回值

返回处理之后数组的元素个数。

范例

Example #1 array_push() 例子

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

以上例程会输出：

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

参见

array_pop() - 将数组最后一个单元弹出（出栈）
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

用户评论:

[#1] golddragon007 [2015-03-25 10:51:18]

I did a performance check, and I saw, if you push more than one value it can be faster the array push, that the normal $array[] version.

Case 1: $array[] = something;
Case 2: array_push($array, $value);
Case 3: array_push($array, $value1, $value2, $value3 [...]); $values are definied
Case 4: array_push($array, $value1, $value2, $value3 [...]); $values are definied, when $array is not empty
Case 5: Case1 + Case 3
Case 6: Result array contains some value (Case 4)
Case 7: Result array contains same value as the push array (Case 4)
-----------------------------------------------------------------------------------------------------------
~~~~~~~~~~~~ Case 1 ~~~~~~~~~~~~
Times: 0.0310 0.0300 0.0290 0.0340 0.0400 0.0440 0.0480 0.0550 0.0570 0.0570
Min: 0.0290
Max: 0.0570
Avg: 0.0425
~~~~~~~~~~~~ Case 2 ~~~~~~~~~~~~
Times: 0.3890 0.3850 0.3770 0.4110 0.4020 0.3980 0.4020 0.4060 0.4130 0.4200
Min: 0.3770
Max: 0.4200
Avg: 0.4003
~~~~~~~~~~~~ Case 3 ~~~~~~~~~~~~
Times: 0.0200 0.0220 0.0240 0.0340 0.0360 0.0410 0.0460 0.0500 0.0520 0.0520
Min: 0.0200
Max: 0.0520
Avg: 0.0377
~~~~~~~~~~~~ Case 4 ~~~~~~~~~~~~
Times: 0.0200 0.0250 0.0230 0.0260 0.0330 0.0390 0.0460 0.0510 0.0520 0.0520
Min: 0.0200
Max: 0.0520
Avg: 0.0367
~~~~~~~~~~~~ Case 5 ~~~~~~~~~~~~
Times: 0.0260 0.0250 0.0370 0.0360 0.0390 0.0440 0.0510 0.0520 0.0530 0.0560
Min: 0.0250
Max: 0.0560
Avg: 0.0419
~~~~~~~~~~~~ Case 6 ~~~~~~~~~~~~
Times: 0.0340 0.0280 0.0370 0.0410 0.0450 0.0480 0.0560 0.0580 0.0580 0.0570
Min: 0.0280
Max: 0.0580
Avg: 0.0462
~~~~~~~~~~~~ Case 7 ~~~~~~~~~~~~
Times: 0.0290 0.0270 0.0350 0.0410 0.0430 0.0470 0.0540 0.0540 0.0550 0.0550
Min: 0.0270
Max: 0.0550
Avg: 0.044

Tester code:
// Case 1
$startTime = microtime(true);
$array = array();
for ($x = 1; $x <= 100000; $x++)
{
$array[] = $x;
}
$endTime = microtime(true);

// Case 2
$startTime = microtime(true);
$array = array();
for ($x = 1; $x <= 100000; $x++)
{
array_push($array, $x);
}
$endTime = microtime(true);

// Case 3
$result = array();
$array2 = array(&$result)+$array;
$startTime = microtime(true);
call_user_func_array("array_push", $array2);
$endTime = microtime(true);

// Case 4
$result = array();
for ($x = 1; $x <= 100000; $x++)
{
$result[] = $x;
}
$array2 = array(&$result)+$array;
$startTime = microtime(true);
call_user_func_array("array_push", $array2);
$endTime = microtime(true);

// Case 5
$result = array();
$startTime = microtime(true);
$array = array(&$result);
for ($x = 1; $x <= 100000; $x++)
{
$array[] = $x;
}
$endTime = microtime(true);

// Case 6
$result = array(1,2,3,4,5,6);
$startTime = microtime(true);
$array = array(&$result);
for ($x = 1; $x <= 100000; $x++)
{
$array[] = $x;
}
$endTime = microtime(true);

// Case 7
$result = array();
for ($x = 1; $x <= 100000; $x++)
{
$result[] = $x;
}
$startTime = microtime(true);
$array = array(&$result);
for ($x = 1; $x <= 100000; $x++)
{
$array[] = $x;
}
$endTime = microtime(true);

[#2] Rob [2014-09-10 08:59:02]

<?php //Push same var into array multiple times if(!function_exists('m_push')){ function m_push($array, $var, $count){ for ($i = 1; $i <= $count; $i++) { $array[] = $var; } return $array; } } ?>

[#3] flobee [2013-11-20 13:25:07]

Be warned using $array "+=" array(1,2,3) or union operations (http://php.net/manual/en/language.operators.array.php)

I think it worked in the past or i havent test it good enough. :-/
(once it worked, once [] was faster than array_push, the past :-D ):

php -r '$a = array(1,2); $a += array(3,4); print_r($a);'
Array (
    [0] => 1
    [1] => 2
)
php -r '$a = array(1,2); $b = array(3,4);$c = $a + $b; print_r($c);'
Array (
    [0] => 1
    [1] => 2
)
php -r '$a = array(1,2); $b = array(2=>3,3=>4);$c = $a + $b; print_r($c);'
Array (
    [0] => 1
    [1] => 2
    [2] => 3
    [3] => 4
)

[#4] hacfi [2013-07-03 02:57:28]

I noticed that under certain circumstances it can be faster to use

<?php call_user_func_array("array_push", array('x' => &$array1) + array_values($array2)); ?>

than

<?php foreach ($array2 as $key => $value) { $array1[] = $value; } ?>

[#5] chris lanx [2013-06-11 00:07:13]

i wanted to do some string manipulation on a specific field from an sql result set and then append the row to the end of an array like this.

[0] =>
    [one] => [val1]
    [two] => [val2]
    [three] => [val3]
    [four] => [val4]
[0] =>
    [one] => [val1]
    [two] => [val2]
    [three] => [val3]
    [four] => [val4]

~I tried array push and couldnt get it sorted, So what i did was this.

while ($row = mysql_fetch_assoc($query)) {

    $row['five'] = str_replace('.','',$row['place']);
    $results[] = $row;
}

resulting in

[0] =>
    [one] => [val1]
    [two] => [val2]
    [three] => [val3]
    [four] => [val4]
    [five] => [val5]
[0] =>
    [one] => [val1]
    [two] => [val2]
    [three] => [val3]
    [four] => [val4]
    [five] => [val5]

[#6] Rodrigo de Aquino [2012-03-30 03:24:10]

If you're going to use array_push() to insert a "$key" => "$value" pair into an array, it can be done using the following:

$data[$key] = $value;

It is not necessary to use array_push.

[#7] Chicna [2012-03-21 10:14:15]

I found a simple way to have an "array_push_array" function, without the references problem when we want to use call_user_func_array(), hope this help :

function array_push_array(array &$array)
{
    $numArgs = func_num_args();
    if(2 > $numArgs)
    {
      trigger_error(sprintf('%s: expects at least 2 parameters, %s given', __FUNCTION__, $numArgs), E_USER_WARNING);
      return false;
    }

    $values = func_get_args();
    array_shift($values);

    foreach($values as $v)
    {
      if(is_array($v))
      {
        if(count($v) > 0)
        {
          foreach($v as $w)
          {
            $array[] = $w;
          }
        }
      }
      else
      {
        $array[] = $v;
      }
    }

    return count($array);
}

[#8] Szorstki [2011-12-27 02:35:35]

With multidimensional arrays it's easy too (somebody posted a sample, but it isn't useful for beginners). Here is a piece of code that should explain everything and much more:

<?php //two classes of objects which will be in multidimensional array class Org { public $name; public function __construct($name) { $this->name = $name; } } class Org2 { public $name; public function __construct($name) { $this->name = $name; } } //main array $arr = array(); //creating first subarray manually //the subarray name must be like first class above $arr['Org'] = array(); //creating second subarray for objects of selected class //in another way $x=2222; //only for creating the sample object $arr[get_class(new Org2("wtf".$x))] = array(); //pushing some new objects to (sub)arrays in (main)array for ($i=0; $i<3; $i++) { $org1 = new Org("tst".$i); $org2 = new Org2("wtf".$i); array_push($arr[get_class($org1)], $org1); array_push($arr[get_class($org2)], $org2); } //printing everything foreach ($arr as $key=>$value) { $counter = 0; echo "=====".$key." (key) | value: ".$value." "; foreach ($value as $key2=>$value2) { if($value2 == null) { //echo "counter: ".$counter." | key: ".$key2; unset($arr[$key][$key2]); } else { print_r($value2); echo " [".$counter."] [".$key2."] "; } $counter++; } } //the additional, second part echo " -------- "; //deleting one of the objects from selected (sub)array unset($arr['Org'][1]); //printing everything again (look at the counter values) foreach ($arr as $key=>$value) { $counter = 0; echo "=====".$key." (key) | value: ".$value." "; foreach ($value as $key2=>$value2) { if($value2 == null) { //echo "counter: ".$counter." | key: ".$key2; unset($arr[$key][$key2]); } else { print_r($value2); echo " [".$counter."] [".$key2."] "; } $counter++; } } ?>

What we get in browser/console:
=====Org (key) | value: Array
Org Object ( [name] => tst0 ) [0] [0]
Org Object ( [name] => tst1 ) [1] [1]
Org Object ( [name] => tst2 ) [2] [2]
=====Org2 (key) | value: Array
Org2 Object ( [name] => wtf0 ) [0] [0]
Org2 Object ( [name] => wtf1 ) [1] [1]
Org2 Object ( [name] => wtf2 ) [2] [2]

--------

=====Org (key) | value: Array
Org Object ( [name] => tst0 ) [0] [0]
Org Object ( [name] => tst2 ) [1] [2]
=====Org2 (key) | value: Array
Org2 Object ( [name] => wtf0 ) [0] [0]
Org2 Object ( [name] => wtf1 ) [1] [1]
Org2 Object ( [name] => wtf2 ) [2] [2]

[#9] yuri [2011-11-30 10:00:25]

If you want to put an element to a specific position in an array, try this function.

<?php function array_put_to_position(&$array, $object, $position, $name = null) { $count = 0; $return = array(); foreach ($array as $k => $v) { // insert new object if ($count == $position) { if (!$name) $name = $count; $return[$name] = $object; $inserted = true; } // insert old object $return[$k] = $v; $count++; } if (!$name) $name = $count; if (!$inserted) $return[$name]; $array = $return; return $array; } ?>

Example :

<?php $a = array( 'a' => 'A', 'b' => 'B', 'c' => 'C', ); print_r($a); array_put_to_position($a, 'G', 2, 'g'); print_r($a); ?>

[#10] aosojnik at gmail dot com [2009-11-23 02:56:56]

If you want to preserve the keys in the array, use the following:

<?php function array_pshift(&$array) { $keys = array_keys($array); $key = array_shift($keys); $element = $array[$key]; unset($array[$key]); return $element; } ?>

[#11] rarioj at gmail dot com [2009-10-04 18:44:57]

This function "Returns the new number of elements in the array."

To find out the last index, use:

<?php $count = array_push($array, $value); $last_index = array_pop(array_keys($array)); ?>

[#12] Anonymous [2009-09-20 02:00:52]

If you need to push the elements of an array onto the end of another, simply use array_splice():

array_splice($array, count($array), 0, $otherArray);

[#13] helpmepro1 at gmail dot com [2009-01-13 13:43:53]

elegant php array combinations algorithm

<?php //by Shimon Dookin function get_combinations(&$lists,&$result,$stack=array(),$pos=0) { $list=$lists[$pos]; if(is_array($list)) foreach($list as $word) { array_push($stack,$word); if(count($lists)==count($stack)) $result[]=$stack; else get_combinations($lists,$result,$stack,$pos+1); array_pop($stack); } } $wordlists= array( array("shimon","doodkin") , array("php programmer","sql programmer","mql metatrader programmer") ); get_combinations($wordlists,$combinations); echo '<xmp>'; print_r($combinations); ?>

[#14] wesleys at opperschaap dot net [2008-10-10 00:58:22]

A function which mimics push() from perl, perl lets you push an array to an array: push(@array, @array2, @array3). This function mimics that behaviour.

<?php function array_push_array(&$arr) { $args = func_get_args(); array_shift($args); if (!is_array($arr)) { trigger_error(sprintf("%s: Cannot perform push on something that isn't an array!", __FUNCTION__), E_USER_WARNING); return false; } foreach($args as $v) { if (is_array($v)) { if (count($v) > 0) { array_unshift($v, &$arr); call_user_func_array('array_push', $v); } } else { $arr[] = $v; } } return count($arr); } $arr = array(0); $arr2 = array(6,7,8); printf("%s\n", array_push_array($arr, array(),array(1,2,3,4,5), $arr2)); print_r($arr); # error.. $arr = "test"; printf("%s\n", array_push_array($arr, array(),array(1,2,3,4,5), $arr2)); ?>

[#15] willdemaine at gmail dot com [2008-08-07 07:00:09]

If you're adding multiple values to an array in a loop, it's faster to use array_push than repeated [] = statements that I see all the time:

<?php class timer { private $start; private $end; public function timer() { $this->start = microtime(true); } public function Finish() { $this->end = microtime(true); } private function GetStart() { if (isset($this->start)) return $this->start; else return false; } private function GetEnd() { if (isset($this->end)) return $this->end; else return false; } public function GetDiff() { return $this->GetEnd() - $this->GetStart(); } public function Reset() { $this->start = microtime(true); } } echo "Adding 100k elements to array with []\n\n"; $ta = array(); $test = new Timer(); for ($i = 0; $i < 100000; $i++) { $ta[] = $i; } $test->Finish(); echo $test->GetDiff(); echo "\n\nAdding 100k elements to array with array_push\n\n"; $test->Reset(); for ($i = 0; $i < 100000; $i++) { array_push($ta,$i); } $test->Finish(); echo $test->GetDiff(); echo "\n\nAdding 100k elements to array with [] 10 per iteration\n\n"; $test->Reset(); for ($i = 0; $i < 10000; $i++) { $ta[] = $i; $ta[] = $i; $ta[] = $i; $ta[] = $i; $ta[] = $i; $ta[] = $i; $ta[] = $i; $ta[] = $i; $ta[] = $i; $ta[] = $i; } $test->Finish(); echo $test->GetDiff(); echo "\n\nAdding 100k elements to array with array_push 10 per iteration\n\n"; $test->Reset(); for ($i = 0; $i < 10000; $i++) { array_push($ta,$i,$i,$i,$i,$i,$i,$i,$i,$i,$i); } $test->Finish(); echo $test->GetDiff(); ?>

Output

$ php5 arraypush.php
X-Powered-By: PHP/5.2.5
Content-type: text/html

Adding 100k elements to array with []

0.044686794281006

Adding 100k elements to array with array_push

0.072616100311279

Adding 100k elements to array with [] 10 per iteration

0.034690141677856

Adding 100k elements to array with array_push 10 per iteration

0.023932933807373

[#16] bxi at apparoat dot nl [2008-05-23 04:29:36]

I've done a small comparison between array_push() and the $array[] method and the $array[] seems to be a lot faster.

<?php $array = array(); for ($x = 1; $x <= 100000; $x++) { $array[] = $x; } ?>
takes 0.0622200965881 seconds

and

<?php $array = array(); for ($x = 1; $x <= 100000; $x++) { array_push($array, $x); } ?>
takes 1.63195490837 seconds

so if your not making use of the return value of array_push() its better to use the $array[] way.

Hope this helps someone.

[#17] alexander dot williamson at gmail dot com [2008-03-26 16:06:05]

This will work to solve the associative array issues:

$aValues[$key] = $value;

Where $key is a unique identifier and $value is the value to be stored. Since the $key works off a string or number, if you already have a $key with the same value as an existing $key, the element will be overwritten.

e.g.

$aValues["one"] = "value of one";
$aValues["two"] = "different value of two!";

gives:
array([one] => "value of one", [two] => "value of two");

but will be overwritten when using the same key (one):

$aValues["one"] = "value of one";
$aValues["one"] = "different value of two!";

will give:

array([one] => "different value of two!");

3686

[#18] darkimmortal at dkimmortal dot com [2008-02-18 11:31:11]

I wrote this function for use with 'latest scores' on a quiz site, but it has many potential uses.

<?php function array_push_limit($array,$add,$limit=10){ array_push($array, $add); do { array_shift($array); $size=count($array); } while($size > $limit); return $array; } ?>
----------
EXAMPLE:
----------
<?php $array=array(1, -5, 23, -66, 33, 54, 3); print_r(array_push_limit($array, "HELLO", 4)); ?>
----------
OUTPUT:
----------
Array
(
 [0] => 33
 [1] => 54
 [2] => 3
 [3] => HELLO
)

[#19] zbde00 at hotmail dot com [2007-07-20 05:59:31]

A very good function to remove a element from array
function array_del($str,&$array)
{
if (in_array($str,$array)==true)
{

foreach ($array as $key=>$value)
{
if ($value==$str) unset($array[$key]);
}
}
}

[#20] Marc Bernet [2006-05-15 09:18:01]

A small and basic implementation of a stack without using an array.

class node
{
var $elem;
var $next;
}
class stack
{
var $next;
function pop()
{
$aux=$this->next->elem;
$this->next=$this->next->next;
return $aux;
}
function push($obj)
{
$nod=new node;
$nod->elem=$obj;
$nod->next=$this->next;
$this->next=$nod;
}
function stack()
{
$this->next=NULL;
}
}

[#21] richard dot udo at gmail dot com [2006-02-09 03:05:37]

Just a typo i think but the code below will actually produce

Array
(
    [0] => a
    [1] => b
    [2] => c
    [3] => Array
        (
            [0] => d
            [1] => e
            [2] => f
        )
)

[#22] egingell at sisna dot com [2006-01-28 06:06:41]

If you push an array onto the stack, PHP will add the whole array to the next element instead of adding the keys and values to the array. If this is not what you want, you're better off using array_merge() or traverse the array you're pushing on and add each element with $stack[$key] = $value.

<?php $stack = array('a', 'b', 'c'); array_push($stack, array('d', 'e', 'f')); print_r($stack); ?>
The above will output this:
Array (
 [0] => a
 [1] => b
 [2] => c
 [3] => Array (
 [0] => a
 [1] => b
 [2] => c
 )
)

[#23] steve at webthoughts d\ot ca [2005-11-12 16:02:06]

Further Modification on the array_push_associative function
1. removes seemingly useless array_unshift function that generates php warning
2. adds support for non-array arguments

<?php // Append associative array elements function array_push_associative(&$arr) { $args = func_get_args(); foreach ($args as $arg) { if (is_array($arg)) { foreach ($arg as $key => $value) { $arr[$key] = $value; $ret++; } }else{ $arr[$arg] = ""; } } return $ret; } $items = array("here" => "now"); $moreitems = array("this" => "that"); $theArray = array("where" => "do we go", "here" => "we are today"); echo array_push_associative($theArray, $items, $moreitems, "five") . ' is the size of $theArray. '; echo "<pre>"; print_r($theArray); echo "</pre>"; ?>

Yields:

4 is the size of $theArray.
Array
(
 [where] => do we go
 [here] => now
 [this] => that
 [five] =>
)

[#24] ludvig dot ericson at gmail dot com [2005-10-31 05:32:43]

Previous comment was not fully imitating the array_push behaviour,
1) does not return number of items pushed
2) can only handle one array to push

> Revised associative_push function with absolute reference of arg1 array; left unchanged if arg2 is empty.

<?php // Append associative array elements function array_push_associative(&$arr) { $args = func_get_args(); array_unshift($args); // remove &$arr argument foreach ($args as $arg) { if (is_array($arg)) { foreach ($arg as $key => $value) { $arr[$key] = $value; $ret++; } } } return $ret; } $theArray = array(); echo array_push_associative($theArray, $items, $moreitems) . ' items added to $theArray.'; ?>

[#25] john [2005-10-19 13:33:05]

A variation of kamprettos' associative array push:

// append associative array elements
function associative_push($arr, $tmp) {
  if (is_array($tmp)) {
    foreach ($tmp as $key => $value) {
      $arr[$key] = $value;
    }
    return $arr;
  }
  return false;
}

$theArray = array();
$theArray = associative_push($theArray, $items);

[#26] kamprettos at yahoo dot com Teguh Iskanto [2005-09-19 05:33:57]

Looking for a way to push data into an associative array and frustrated to know that array_push() can't do the job ?

here's my Scenario :
-------------------
I need to relate system command output into an associative array like these :

[sge@digital_db work]$ /usr/local/apache/htdocs/work/qhost.sh -h t1 -F | awk '{if(NR>4) print $1}' | sed 's/hl://g'
arch=lx24-amd64
num_proc=2.000000
mem_total=3.808G
swap_total=3.907G
virtual_total=7.715G
load_avg=0.000000
load_short=0.000000
load_medium=0.000000
load_long=0.000000
mem_free=3.510G
swap_free=3.907G
virtual_free=7.417G
mem_used=305.242M
swap_used=0.000
virtual_used=305.242M
cpu=0.000000
np_load_avg=0.000000
np_load_short=0.000000
np_load_medium=0.000000
np_load_long=0.000000

how I did it :
<?php php # get into the system command output $assoc_cmd =`$work_dir/qhost.sh -h $host_resource -F | awk '{if(NR>4) print $1}'| sed 's/hl://g' ` ; # split the "\n" character $assoc_row = explode("\n", chop($assoc_cmd)); # get the index row $idx_row = count($assoc_row) - 1 ; # initialize the associative array $host_res_array = array(); for ($i = 0 ; $i<= $idx_row ; $i++) { # get params & values list($host_param,$host_val) = explode("=",$assoc_row[$i]); # populate / push data to assoc array $host_res_array[$host_param]= $host_val ; } echo "<pre> Architecture : </pre>\n" ; echo $host_res_array['arch'] ; echo "<pre> Mem Total : </pre>\n" ; echo $host_res_array['mem_tot']; ?>

Hope this helps ! :)

[#27] bk at quicknet dot nl [2005-09-04 01:51:17]

Add elements to an array before or after a specific index or key:

<?php function array_push_before($src,$in,$pos){ if(is_int($pos)) $R=array_merge(array_slice($src,0,$pos), $in, array_slice($src,$pos)); else{ foreach($src as $k=>$v){ if($k==$pos)$R=array_merge($R,$in); $R[$k]=$v; } }return $R; } function array_push_after($src,$in,$pos){ if(is_int($pos)) $R=array_merge(array_slice($src,0,$pos+1), $in, array_slice($src,$pos+1)); else{ foreach($src as $k=>$v){ $R[$k]=$v; if($k==$pos)$R=array_merge($R,$in); } }return $R; } // Examples: $src=array("A","B","C"); $in=array("X","Y"); var_dump(array_push_before($src,$in,1)); var_dump(array_push_after($src,$in,1)); $src=array('a'=>"A",'b'=>"B",'c'=>"C"); $in=array('x'=>"X",'y'=>"Y"); var_dump(array_push_before($src,$in,1)); var_dump(array_push_before($src,$in,'b')); var_dump(array_push_after($src,$in,1)); var_dump(array_push_after($src,$in,'b')); ?>

[#28] ciprian dot amariei at gmail com [2005-08-30 14:47:51]

regarding the speed of oneill's solution to insert a value into a non-associative array,  I've done some tests and I found that it behaves well if you have a small array and more insertions, but for a huge array and a little insersions I sugest  using this function:

function array_insert( &$array, $index, $value ) {
   $cnt = count($array);

   for( $i = $cnt-1; $i >= $index; --$i ) {
       $array[ $i + 1 ] = $array[ $i ];
   }
   $array[$index] = $value;
}

or if you are a speed adicted programmer (same situation: big array, few insertions) use this:

array_splice ( $array, $offset, 0, $item );

item may also be an array of values ;).

[#29] Phil Davies [2005-07-18 03:51:09]

As someone pointed out the array_push() function returns the count of the array not the key of the new element. As it was the latter function i required i wrote this very simple replacement.

function array_push2(&$array,$object,$key=null){
    $keys = array_keys($array);
    rsort($keys);
    $newkey = ($key==null)?$keys[0]+1:$key;
    $array[$newkey] = $object;
    return $newkey;
}

[#30] oneill at c dot dk [2005-06-03 13:50:32]

To insert a value into a non-associative array, I find this simple function does the trick:

function insert_in_array_pos($array, $pos, $value)
{
$result = array_merge(array_slice($array, 0 , $pos), array($value), array_slice($array, $pos));
return $result;
}

Seems an awful lot simpler than the iterative solutions given above...

[#31] aaron dot hawley at uvm dot edu [2005-05-27 11:36:42]

Skylifter notes on 20-Jan-2004 that the [] empty bracket notation does not return the array count as array_push does. There's another difference between array_push and the recommended empty bracket notation.

Empy bracket doesn't check if a variable is an array first as array_push does. If array_push finds that a variable isn't an array it prints a Warning message if E_ALL error reporting is on.

So array_push is safer than [], until further this is changed by the PHP developers.

[#32] josh at digitalfruition dot com [2005-02-14 10:17:27]

Note that array_push() will, as described, return the COUNT of the array after adding a new item, not necessarily the INDEX of that new item:

<?php $array = array(3 => 'three', 5 => 'five'); echo "\$array = "; print_r($array); echo "\n\n"; $to_push = array(1,2,4,); foreach($to_push as $var) { echo "calling array_push(\$array,$var); retval is "; echo array_push($array,$var); echo "\n"; } echo "\$array = "; print_r($array); ?>

The output of above is:

$array = Array
(
 [3] => three
 [5] => five
)

calling array_push($array,1); retval is 4
calling array_push($array,2); retval is 5
calling array_push($array,4); retval is 6
$array = Array
(
 [3] => three
 [5] => five
 [7] => seven
 [8] => 1
 [9] => 2
 [10] => 4
)

Notice how when array_push($array,1) was called, the new element has a key of 8 but array_push() returns 4.

[#33] andrew at cgipro dot com [2005-02-02 15:18:51]

Need a real one-liner for adding an element onto a new array name?

$emp_list_bic = $emp_list + array(c=>"ANY CLIENT");

CONTEXT...
drewdeal: this turns out to be better and easier than array_push()
patelbhadresh: great!... so u discover new idea...
drewdeal: because you can't do: $emp_list_bic = array_push($emp_list, c=>"ANY CLIENT");
drewdeal: array_push returns a count and affects current array.. and does not support set keys!
drewdeal: yeah. My one-liner makes a new array as a derivative of the prior array

[#34] aron [2004-02-24 02:48:22]

The problem with array_push is that it is pass by value. If you are dealing with objects whose inner state may change at any time, you need a push and pop who return the actual objects, rather than copies of them.
After some difficulty and board assistance, I have these methods. I've tested them, and they seem to work fine.

<?php function push(&$array, &$object){ $array[] =& $object; } function & pop(&$array){ return array_pop($array); } // [Test Code] class TestObject{ var $value = 0; function getValue(){ return $this->value; } function setValue($mixed){ $this->value = $mixed; } } $myarr = array(); $tmp =& new TestObject(); $tmp2 =& new TestObject(); $tmp->setValue(2); $tmp2->setValue(3); push($myarr, $tmp); push($myarr, $tmp2); $tmp->setValue(4); $tmp2->setValue(6); $val = pop($myarr); print "popped value: ".$val->getValue()." "; print "values in internal array: "; foreach ($myarr as $key=>$value){ print "key: $key, object: $value, value: "; print $value->getValue()." "; } // [/TestCode] ?>

[#35] skiflyer [2004-01-20 16:05:07]

However, don't forget that array_push() does more than [], it also performs a count and returns the value.

Modifying your code ever so slightly (see below), this puts array_push in the lead (not suprisingly). So my conclusion would be that if I care about the number of elements in the array, then I'd use array_push(), if I don't (which is usually the case), then I'd use the [] method.

Results...
[] method: 0.34943199
push method: 0.31505919
difference: -0.03437280

Modified section of code...
$s_test_begin = FullMicroTime();
for($i = 0; $i <= 50000; $i++) { $num_tot = array_push($test2, $i); }
$s_test_end = FullMicroTime();

$f_test_begin = FullMicroTime();
for($i = 0; $i <= 50000; $i++) { $test[] = $i; $num_tot = count($test); }
$f_test_end = FullMicroTime();

[#36] daevid at daevid dot com [2003-02-16 20:38:20]

Sadly, array_push() does not create an array if the array doesn't exist. So if you're pushing the first element onto an array, you need to check and create it manually...

<?php if ( !is_array($myArray) ) $myArray= array(); array_push($myArray, $myElement); ?>

[#37] bart at framers dot nl [2001-09-27 04:16:10]

Array_push also works fine with multidimensional arrays. Just make sure the element is defined as an array first.

<?php $array["element"][$element]["element"] = array(); array_push ($array["element"][$element]["element"], "banana"); ?>