PHP 5.6.0beta1 released

array_pad

(PHP 4, PHP 5)

array_padRellena un array a la longitud especificada con un valor

Descripción

array array_pad ( array $array , int $size , mixed $value )

array_pad() devuelve una copia de array rellenada al tamaño especificado por size con el valor value. Si size es positivo, el array se rellena hacia la derecha, si es negativo hacia la izquierda. Si el valor absoluto de size es menor o igual a la longitud de array, no se lleva a cabo el relleno. Es posible añadir como máximo 1048576 elementos de una sola vez.

Parámetros

array

Array inicial de valores a rellenar.

size

Nuevo tamaño del array.

value

Valor a rellenar si array es menor que size.

Valores devueltos

Devuelve una copia de array rellenada al espacio especificado por size con el valor value. Si size es positivo el array es relleno hacia la derecha, si es negativo hacia la izquierda. Si el valor absoluto de size es menor o igual que la longitud de array, no se lleva a cabo el relleno.

Ejemplos

Ejemplo #1 Ejemplo de array_pad()

<?php
$input 
= array(12109);

$result array_pad($input50);
// el resultado es array(12, 10, 9, 0, 0)

$result array_pad($input, -7, -1);
// el resultado es array(-1, -1, -1, -1, 12, 10, 9)

$result array_pad($input2"noop");
// sin relleno
?>

Ver también

  • array_fill() - Llena un array con valores
  • range() - Crear un array que contiene un rango de elementos

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User Contributed Notes 11 notes

up
3
Anonymous
10 years ago
One way to initialize a 20x20 multidimensional array. 

<?php
$a
= array();
$b = array();
$b = array_pad($b,20,0);
$a = array_pad($a,20,$b);
?>
up
3
tugla
5 years ago
Beware, if you try to pad an associative array using numeric keys, your keys will be re-numbered.

<?php
$a
= array('size'=>'large', 'number'=>20, 'color'=>'red');
print_r($a);
print_r(array_pad($a, 5, 'foo'));

// use timestamps as keys
$b = array(1229600459=>'large', 1229604787=>20, 1229609459=>'red');
print_r($b);
print_r(array_pad($b, 5, 'foo'));
?>

yields this:
------------------
Array
(
    [size] => large
    [number] => 20
    [color] => red
)
Array
(
    [size] => large
    [number] => 20
    [color] => red
    [0] => foo
    [1] => foo
)
Array
(
    [1229600459] => large
    [1229604787] => 20
    [1229609459] => red
)
Array
(
    [0] => large
    [1] => 20
    [2] => red
    [3] => foo
    [4] => foo
)
up
3
mwwaygoo at hotmail dot com
10 years ago
little older, a little wiser.

ksort() will order the array back into its normal order again
so:

<?php
$myArr
= array(2 => 'two', 4 => 'four');

$newArr = array_pad(array(), 6, 'FILLED');
$newArr =$myArr+$newArr;
ksort($newArr);
?>

Will give :
Array ( [0] => FILLED [1] => FILLED [2] => two [3] => FILLED [4] => four [5] => FILLED )
up
2
mwwaygoo at hotmail dot com
11 years ago
OR you could do this

<?php
$myArr
= array(2 => 'three', 3 => 'four');

$newArr = array_pad(array(), 4, 'FILLED');
$newArr =$myArr+$newArr;
?>

This gives your desired result BUT the ordering is a little wierd, because of the order they were added. Indexes are okay though and that is what you wanted.

print_r($newArr) outputs
Array ( [2] => three [3] => four [0] => FILLED [1] => FILLED )

hope this helps
up
2
daarius at hotmail dot com
11 years ago
yes that is true. But, if the index of the array is 2=two, 3=three

and i want 4 more keys to be filled. But, not just filled anywhere, but i want to maintain the key index.

so, i would like to have 0=FILLED, 1=FILLED ... 4=FILLED, 5=FILLED

now i got 4 more keys padded with my string.

We can do this "if" we know the missing keys, but if we dont, then it would be nice for array_pad() or perhaps some new function to do this?

obviously we can achive this by looping through the array using array_key_exists(), and if you dont find the key, simply create + fill it.
regards,
Daarius...
up
2
scott*hurring.com
11 years ago
to the previous commenter -- if you read the manual entry, you'd see that a negative pad_size will put the pad values at the front of the array.
up
0
slava-san at mail dot ru
9 months ago
// insert element to array
function array_insert(&$arr, $pos, $new_el=null) {
    $arraypad = array_pad($arr, count($arr)+1, 0);
    for ($i=count($arr)-1; $i>=$pos; $i--) {
        $arr[$i+1] = $arr[$i];
        if ($i == $pos) {
            $arr[$i] = $new_el;
        }
    }
}

$digits = array();
$digits[0] = 0;
$digits[1] = 1;
$digits[2] = 2;
$digits[3] = 3;
$digits[4] = 4;
$digits[5] = 5;
echo "was: "; var_dump($digits);

array_insert($digits, 3, 100);
echo "new: "; var_dump($digits);
up
0
hk, StrApp Bussiness Solutions
7 years ago
A simple example for array_pad()

the syntax is as follows: array_pad(array(), (+/-)int, value)

where "array" is the array to which the value is to be added,

"(+/-) int" is a value that decides the length of the array(it should be greater than the length of the array.
if its a negative number then the value will be added at the left of the array else it will be added to the right.

"values" denotes the value to be added to the array

lets try an example:

<?php

$digits
= array();
$digits[0] = 1;
$digits[1] = 2;
$digits[2] = 3;
$arraypad = array_pad($digits, -4, "0");
print_r($arraypad);

?>

output:

Array ( [0] => 0 [1] => 1 [2] => 2 [3] => 3 )
up
0
goffrie at sympatico dot ca
11 years ago
To daarius - you mean you have...

[2]=>"two"
[3]=>"three"

and you want...

[0]=>"FILLED"
[1]=>"FILLED"
[2]=>"two"
[3]=>"three"
[4]=>"FILLED"
[5]=>"FILLED"

If so, then the following code...

<?php
$array
= array(2 => "two", 3 => "three");
$array = array_pad($array, count($array)+2, "FILLED");
$num = -(count($array)+2);
$array = array_pad($array, $num, "FILLED");
print_r($array);
?>

will return:
Array ( [0] => FILLED [1] => FILLED [2] => two [3] => three [4] => FILLED [5] => FILLED )
The ordering should be okay,...
up
-1
oaev at mail dot ru
9 years ago
Easy way to get an array contains 5 random numbers from 0 to 9:

$rand_arr = array_rand( array_pad( array(), 10, 1 ), 5 );
up
-2
sonu50imedbvu at gmail dot com(Sonu Jaiswal)
3 years ago
Just an info about the value of "$pad_size" ,

If we set the value of "$pad_size" from -3 to 3,

It will produce the output like:

<?php
$result
= array_pad($input, -3, "noop");
//result is array(12, 10, 9)

$result = array_pad($input, 3, "noop");
//result is array(12, 10, 9)
?>

means array will remain the same.
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