array_pad

(PHP 4, PHP 5)

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

Descripción

array array_pad ( array $input , int $pad_size , mixed $pad_value )

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

Parámetros

input: Array inicial de valores a rellenar.
pad_size: Nuevo tamaño del array.
pad_value: Valor a rellenar si input es menor que pad_size.

Valores devueltos

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

Ejemplos

Example #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

array_pop

array_multisort

Last updated: Fri, 20 May 2011

add a note User Contributed Notes array_pad

sonu50imedbvu at gmail dot com(Sonu Jaiswal) 12-Jan-2011 08:53


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.

tugla 18-Dec-2008 05:23


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


)

hk, StrApp Bussiness Solutions 08-Jan-2007 10:15


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 )

oaev at mail dot ru 22-Oct-2004 06:48


Easy way to get an array contains 5 random numbers from 0 to 9:



$rand_arr = array_rand( array_pad( array(), 10, 1 ), 5 );

29-Feb-2004 05:00


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);


?>

mwwaygoo at hotmail dot com 16-Jan-2004 04:02


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 )

goffrie at sympatico dot ca 24-Mar-2003 01:06


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,...

mwwaygoo at hotmail dot com 19-Sep-2002 04:39


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

daarius at hotmail dot com 23-Jul-2002 02:36


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...

scott*hurring.com 19-Jul-2002 11:20


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.

ethanhunt314 at hotmail dot com 10-Dec-2000 12:25


This is useful when using next() and prev() function in a while loop to traverse an array. 





For example the following code will only output up to 8.





<?php


$test[] = "1";


$test[] = "2";


$test[] = "3";


$test[] = "4";


$test[] = "5";


$test[] = "6";


$test[] = "7";


$test[] = "8";


$test[] = "9";


$test[] = "10";


$test[] = " ";


$test[] = " ";


$test[] = " ";





$count = count($test);





while($i < $count) {





$now = current($test);


echo "<p>$now</p>";





next($test);


next($test);


next($test);


prev($test);


prev($test);


prev($test);








$i++;


next($test);


}


?>





But if you use:


$test = array_pad($test, 13, " ");





you will get all of your output.

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