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 $value1 [, 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;
?>
并对每个传入的值重复以上动作。

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。

value1

要压入 array 末尾的第一个值。

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

User Contributed Notes

gfuente at garrahan dot gov dot ar 21-Jan-2017 04:33
If the element to be pushed onto the end of array is an array you will receive the following error message:

Unknown Error, value: [8] Array to string conversion

I tried both: (and works, but with the warning message)

            $aRol = array( $row[0], $row[1], $row[2] );
            $aRoles[] = $aRol;

and
            array_push( $aRoles, $aRol);

The correct way:

            $cUnRol = implode("(",array( $row[0], $row[1], $row[2] ) );
            array_push( $aRoles, $cUnRol );

thanks.
colecooper2005 at icloud dot com 07-Nov-2016 03:44
When developing a pocketmine plugin, a good way to add stuff to a YAML table is

$table=$this->config->get("Table");
array_push($table, "New Value for table");
$this->config->set("Table", $table);
raat1979 at gmail dot com 23-Apr-2016 11:39
Unfortunately array_push returns the new number of items in the array
It does not give you the key of the item you just added, in numeric arrays you could do -1, you do however need to be sure that no associative key exists as that would break the assumption

It would have been better if array_push would have returned the key of the item just added like the below function
(perhaps a native variant would be a good idea...)

<?php

if(!function_exists('array_add')){
    function array_add(array &$array,$value /*[, $...]*/){
        $values = func_get_args();     //get all values
        $values[0]= &$array;        //REFERENCE!
        $org=key($array);              //where are we?
        call_user_func_array('array_push',$values);
        end($array);                 // move to the last item
        $key = key($array);         //get the key of the last item
        if($org===null){
            //was at eof, added something, move to it
            return $key;
        }elseif($org<(count($array)/2)){ //somewhere in the middle +/- is fine
            reset($array);
            while (key($array) !== $org) next($List);
        }else{
            while (key($array) !== $org) prev($List);
        }
        return $key;
    }
}
echo "<pre>\n";
$pr = array('foo'=>'bar','bar'=>'foo');
echo "Taken array;";
print_r($pr);

echo "\npush 1 returns ".array_push($pr,1)."\n";
echo "------------------------------------\n";
$pr = array('foo'=>'bar','bar'=>'foo');
echo "\npush 2 returns ".array_push($pr,1,2)."\n";
echo "------------------------------------\n";
$pr = array('foo'=>'bar','bar'=>'foo');
echo "\n add 1 returns ".array_add($pr,2)."\n\n";
echo "------------------------------------\n";
$pr = array('foo'=>'bar','bar'=>'foo');
echo "\n add 2 returns ".array_add($pr,1,2)."\n\n";
echo "<pre/>\n\n";
?>
Outputs:
Taken array;Array
(
    [foo] => bar
    [bar] => foo
)

push 1 returns 3
------------------------------------

push 2 returns 4
------------------------------------

 add 1 returns 0

------------------------------------

 add 2 returns 1
mrgreen dot webpost at gmail dot com 09-Mar-2016 11:11
Rodrigo de Aquino asserted that instead of using array_push to append to an associative array you can instead just do...

        $data[$key] = $value;

...but this is actually not true. Unlike array_push and even...

        $data[] = $value;

...Rodrigo's suggestion is NOT guaranteed to append the new element to the END of the array. For instance...

        $data['one'] = 1;
        $data['two'] = 2;
        $data['three'] = 3;
        $data['four'] = 4;
 
...might very well result in an array that looks like this...

       [ "four" => 4, "one" => 1, "three" => 3, "two" => 2 ]

I can only assume that PHP sorts the array as elements are added to make it easier for it to find a specified element by its key later. In many cases it won't matter if the array is not stored internally in the same order you added the elements, but if, for instance, you execute a foreach on the array later, the elements may not be processed in the order you need them to be.

If you want to add elements to the END of an associative array you should use the unary array union operator (+=) instead...

       $data['one'] = 1;
       $data += [ "two" => 2 ];
       $data += [ "three" => 3 ];
       $data += [ "four" => 4 ];

You can also, of course, append more than one element at once...

       $data['one'] = 1;
       $data += [ "two" => 2, "three" => 3 ];
       $data += [ "four" => 4 ];

Note that like array_push (but unlike $array[] =) the array must exist before the unary union, which means that if you are building an array in a loop you need to declare an empty array first...

       $data = [];
       for ( $i = 1; $i < 5; $i++ ) {
              $data += [ "element$i" => $i ];
       }

...which will result in an array that looks like this...

      [ "element1" => 1, "element2" => 2, "element3" => 3, "element4" => 4 ]
golddragon007 25-Mar-2015 07:51
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);
flobee 20-Nov-2013 10:25
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
)
Rodrigo de Aquino 30-Mar-2012 12:24
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.
Chicna 21-Mar-2012 07:14
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);
}
yuri 30-Nov-2011 07:00
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);

/*
Array
(
    [a] => A
    [b] => B
    [c] => C
)
Array
(
    [a] => A
    [b] => B
    [g] => G
    [c] => C
)
*/
?>
aosojnik at gmail dot com 23-Nov-2009 11:56
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;
}
?>
rarioj at gmail dot com 05-Oct-2009 03:44
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));
?>
helpmepro1 at gmail dot com 13-Jan-2009 10:43
elegant php array combinations algorithm

<?

//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);

?>
wesleys at opperschaap dot net 10-Oct-2008 09:58
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));

?>
willdemaine at gmail dot com 07-Aug-2008 04:00
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
bxi at apparoat dot nl 23-May-2008 01:29
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.
alexander dot williamson at gmail dot com 27-Mar-2008 01:06
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
zbde00 at hotmail dot com 20-Jul-2007 02:59
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]);
        }
    }
}
Marc Bernet 15-May-2006 06:18
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;
    }    
}
egingell at sisna dot com 28-Jan-2006 03:06
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
  )
)
steve at webthoughts d\ot ca 13-Nov-2005 01:02
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

<?
// 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.<br />';
   
echo "<pre>";
print_r($theArray);
echo "</pre>";

?>

Yields:

4 is the size of $theArray.
Array
(
    [where] => do we go
    [here] => now
    [this] => that
    [five] =>
)
john 19-Oct-2005 10:33
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);
kamprettos at yahoo dot com Teguh Iskanto 19-Sep-2005 02:33
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

# 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 ! :)
bk at quicknet dot nl 04-Sep-2005 10:51
Add elements to an array before or after a specific index or key:

<?php

/**
 * @return array
 * @param array $src
 * @param array $in
 * @param int|string $pos
*/
function array_push_before($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;
}

/**
 * @return array
 * @param array $src
 * @param array $in
 * @param int|string $pos
*/
function array_push_after($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));
/* array_push_before, no-key array
array(5) {
  [0]=>
  string(1) "A"
  [1]=>
  string(1) "X"
  [2]=>
  string(1) "Y"
  [3]=>
  string(1) "B"
  [4]=>
  string(1) "C"
}*/

var_dump(array_push_after($src,$in,1));
/* array_push_after, no-key array
array(5) {
  [0]=>
  string(1) "A"
  [1]=>
  string(1) "B"
  [2]=>
  string(1) "X"
  [3]=>
  string(1) "Y"
  [4]=>
  string(1) "C"
}*/

$src=array('a'=>"A",'b'=>"B",'c'=>"C");
$in=array('x'=>"X",'y'=>"Y");

var_dump(array_push_before($src,$in,1));
/* array_push_before, key array, before index insert
array(5) {
  ["a"]=>
  string(1) "A"
  ["x"]=>
  string(1) "X"
  ["y"]=>
  string(1) "Y"
  ["b"]=>
  string(1) "B"
  ["c"]=>
  string(1) "C"
}*/

var_dump(array_push_before($src,$in,'b'));
/* array_push_before, key array, before key insert
array(5) {
  ["a"]=>
  string(1) "A"
  ["x"]=>
  string(1) "X"
  ["y"]=>
  string(1) "Y"
  ["b"]=>
  string(1) "B"
  ["c"]=>
  string(1) "C"
}*/

var_dump(array_push_after($src,$in,1));
/* array_push_after, key array, after index insert
array(5) {
  ["a"]=>
  string(1) "A"
  ["b"]=>
  string(1) "B"
  ["x"]=>
  string(1) "X"
  ["y"]=>
  string(1) "Y"
  ["c"]=>
  string(1) "C"
}*/

var_dump(array_push_after($src,$in,'b'));
/* array_push_after, key array, after key insert
array(5) {
  ["a"]=>
  string(1) "A"
  ["b"]=>
  string(1) "B"
  ["x"]=>
  string(1) "X"
  ["y"]=>
  string(1) "Y"
  ["c"]=>
  string(1) "C"
}*/

?>
ciprian dot amariei at gmail com 30-Aug-2005 11:47
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 ;).
Phil Davies 18-Jul-2005 12:51
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;
}
oneill at c dot dk 03-Jun-2005 10:50
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...
aaron dot hawley at uvm dot edu 27-May-2005 08:36
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.
andrew at cgipro dot com 03-Feb-2005 12:18
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
bart at framers dot nl 27-Sep-2001 01:16
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");
?>