PHP: array_fill

Description

array array_fill ( int start_index, int num, mixed value )

array_fill() fills an array with num entries of the value of the value parameter, keys starting at the start_index parameter. Note that num must be a number greater than zero, or PHP will throw a warning.

Example 1. array_fill() example

<?php $a = array_fill(5, 6, 'banana'); print_r($a); ?>
$a now is:
Array ( [5] => banana [6] => banana [7] => banana [8] => banana [9] => banana [10] => banana )

See also str_repeat() and range().

User Contributed Notes
array_fill

csst0266 at cs dot uoi dot gr
11-Aug-2004 12:32


This is what I recently did to quickly create a two dimensional array (10x10), initialized to 0:



<?php

  $a = array_fill(0, 10, array_fill(0, 10, 0));

?>



This should work for as many dimensions as you want, each time passing to array_fill() (as the 3rd argument) another array_fill() function.

jausion at hotmail-dot-com
29-Mar-2003 01:50


For PHP < 4.2.0 users:



Add this to your script:

if (!function_exists('array_fill')) {

   require_once('array_fill.func.php');

}



and the array_fill.func.php file:



<?php



// For PHP version < 4.2.0 missing the array_fill function,

// I provide here an alternative. -Philippe



function array_fill($iStart, $iLen, $vValue) {

    $aResult = array();

    for ($iCount = $iStart; $iCount < $iLen + $iStart; $iCount++) {

        $aResult[$iCount] = $vValue;

    }

    return $aResult;

}



?>

25-Aug-2002 03:59


array_fill() cannot be used to setup only missing keys in an array. This  may be necessary for example before using implode()  on a sparse filled array.


The solution is to use this function:





<?php


function array_setkeys(&$array, $fill = NULL) {


  $indexmax = -1;


  for (end($array); $key = key($array); prev($array)) {


    if ($key > $indexmax)


      $indexmax = $key;


  }


  for ($i = 0; $i <= $indexmax; $i++) {


    if (!isset($array[$i]))


      $array[$i] = $fill;


  }


  ksort($array);


}


?>





This is usefull in some situations where you don't know which key index was filled and you want to preserve the association between a positioned field in an imploded array and the key index when exploding it.