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 — 配列を指定した値で埋める
説明
array array_fill ( int $start_index, int $num, mixed $value )パラメータ value を値とする num 個のエントリからなる配列を埋めます。 この際、キーは、start_index パラメータから開始します。
パラメータ
- start_index
返される配列の最初のインデックス。
- num
挿入する要素数。
- value
要素に使用する値。
返り値
値を埋めた配列を返します。
エラー / 例外
num が 1 より小さい場合に E_WARNING が発生します。
例
例 240. array_fill() の例
<?php
$a = array_fill(5, 6, 'banana');
print_r($a);
?>
上の例の出力は以下となります。
Array
(
[5] => banana
[6] => banana
[7] => banana
[8] => banana
[9] => banana
[10] => banana
)
参考
| str_repeat() |
| range() |
array_fill
caliban at darklock dot com
23-May-2005 11:42
23-May-2005 11:42
csst0266 at cs dot uoi dot gr
12-Aug-2004 02:32
12-Aug-2004 02:32
This is what I recently did to quickly create a two dimensional array (10x10), initialized to 0:
<?php
$a = array_fill(0, 10, array_fill(0, 10, 0));
?>
This should work for as many dimensions as you want, each time passing to array_fill() (as the 3rd argument) another array_fill() function.
jausion at hotmail-dot-com
29-Mar-2003 04:50
29-Mar-2003 04:50
For PHP < 4.2.0 users:
Add this to your script:
if (!function_exists('array_fill')) {
require_once('array_fill.func.php');
}
and the array_fill.func.php file:
<?php
// For PHP version < 4.2.0 missing the array_fill function,
// I provide here an alternative. -Philippe
function array_fill($iStart, $iLen, $vValue) {
$aResult = array();
for ($iCount = $iStart; $iCount < $iLen + $iStart; $iCount++) {
$aResult[$iCount] = $vValue;
}
return $aResult;
}
?>
26-Aug-2002 05:59
array_fill() cannot be used to setup only missing keys in an array. This may be necessary for example before using implode() on a sparse filled array.
The solution is to use this function:
<?php
function array_setkeys(&$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.