array_pad

(PHP 4, PHP 5, PHP 7, PHP 8)

array_pad — Rellena un array a la longitud especificada con un valor

Descripción

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

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(12, 10, 9);

$result = array_pad($input, 5, 0);
// 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)

$result = array_pad($input, 2, "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 8 notes

down

tugla ¶

16 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

)

down

goffrie at sympatico dot ca ¶

21 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,...

down

scott*hurring.com ¶

22 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.

down

mwwaygoo at hotmail dot com ¶

20 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 )

down

Anonymous ¶

20 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);

?>

down

-1

hk, StrApp Bussiness Solutions ¶

17 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 )

down

-2

daarius at hotmail dot com ¶

22 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...

down

-3

mwwaygoo at hotmail dot com ¶

22 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

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