array_fill_keys
To better handle the problem of sparse array completion mentioned a couple years ago...
What you really need in this scenario is an empty array containing all the desired keys, and a sparse array containing the keys and values you want overridden. This PHP5 function does that. (The PEAR package PHP_Compat should be able to fill in the gap -- array_combine() -- for a 4.3 install, if necessary.)
<?php
function array_complete(
$keys="", // array of keys you need filled, in order
$sparse="" // sparse array to override blanks
)
{
if(!is_array($sparse))
$sparse=array();
if(!is_array($keys))
return $sparse;
return array_merge(
array_combine( // create an associative array
$keys, // your list of keys
array_fill( // blank value for each key
0,count(
$keys
),""
)
),$sparse // merge with your incomplete array
);
}
?>
This merges in your sparse array (inserting any additional keys in that array after the ones you've specified), placing its values in the key order you specify, leaving all the other values blank.
Test call: var_dump(array_complete(array("test1", "test2", "test3", "test4", "test5"), array("test3" => "test3", "test1" => "test1", "garbage" => "garbage")));
Result: array(6) {
["test1"]=>
string(5) "test1"
["test2"]=>
string(0) ""
["test3"]=>
string(5) "test3"
["test4"]=>
string(0) ""
["test5"]=>
string(0) ""
["garbage"]=>
string(7) "garbage"
}
array_fill
(PHP 4 >= 4.2.0, PHP 5)
array_fill — Fill an array with values
Description
Fills an array with num entries of the value of the value parameter, keys starting at the start_index parameter.
Parameters
- start_index
-
The first index of the returned array
- num
-
Number of elements to insert
- value
-
Value to use for filling
Return Values
Returns the filled array
Errors/Exceptions
Throws a E_WARNING if num is less than one.
Examples
Example #1 array_fill() example
<?php
$a = array_fill(5, 6, 'banana');
$b = array_fill(-2, 2, 'pear');
print_r($a);
print_r($b);
?>
The above example will output:
Array ( [5] => banana [6] => banana [7] => banana [8] => banana [9] => banana [10] => banana ) Array ( [-2] => pear [0] => pear )
Notes
See also the Arrays section of manual for a detailed explanation of negative keys.
add a note
User Contributed Notesarray_fill
caliban at darklock dot com
23-May-2005 05:42
23-May-2005 05:42
csst0266 at cs dot uoi dot gr
11-Aug-2004 08:32
11-Aug-2004 08:32
This is what I recently did to quickly create a two dimensional array (10x10), initialized to 0:
<?php
$a = array_fill(0, 10, array_fill(0, 10, 0));
?>
This should work for as many dimensions as you want, each time passing to array_fill() (as the 3rd argument) another array_fill() function.
jausion at hotmail-dot-com
29-Mar-2003 09:50
29-Mar-2003 09:50
For PHP < 4.2.0 users:
Add this to your script:
if (!function_exists('array_fill')) {
require_once('array_fill.func.php');
}
and the array_fill.func.php file:
<?php
// For PHP version < 4.2.0 missing the array_fill function,
// I provide here an alternative. -Philippe
function array_fill($iStart, $iLen, $vValue) {
$aResult = array();
for ($iCount = $iStart; $iCount < $iLen + $iStart; $iCount++) {
$aResult[$iCount] = $vValue;
}
return $aResult;
}
?>
25-Aug-2002 11:59
array_fill() cannot be used to setup only missing keys in an array. This may be necessary for example before using implode() on a sparse filled array.
The solution is to use this function:
<?php
function array_setkeys(&$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.