array_fill_keys

(PHP 5 >= 5.2.0, PHP 7, PHP 8)

array_fill_keysキーを指定して、配列を値で埋める

説明

array_fill_keys(array $keys, mixed $value): array

パラメータ value で指定した値で配列を埋めます。 キーとして、配列 keys で指定した値を使用します。

パラメータ

keys

キーとして使用する値の配列。キーとして無効な値は string に変換されます。

value

埋めたい値。

戻り値

値を埋めた配列を返します。

例1 array_fill_keys() の例

<?php
$keys
= array('foo', 5, 10, 'bar');
$a = array_fill_keys($keys, 'banana');
print_r($a);
?>

上の例の出力は以下となります。

Array
(
    [foo] => banana
    [5] => banana
    [10] => banana
    [bar] => banana
)

参考

  • array_fill() - 配列を指定した値で埋める
  • array_combine() - 一方の配列をキーとして、もう一方の配列を値として、ひとつの配列を生成する

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User Contributed Notes 10 notes

up
66
sergli at nigma dot ru
12 years ago
<?php
$a
= array("1");

var_dump(array_fill_keys($a, "test"));
?>

array(1) {
  [1]=>
  string(4) "test"
}

now string key "1" become an integer value 1, be careful.
up
3
ray.paseur sometimes uses gmail
2 years ago
Get an associative array of zeros for counting letter frequency

<?php
$ltrs
= array_fill_keys( range('a', 'z'), 0 );
up
30
atul dot kr_singh at hotmail dot com
11 years ago
If an associative array is used as the second parameter of array_fill_keys, then the associative array will be appended in all the values of the first array.
e.g.
<?php
$array1
= array(
   
"a" => "first",
   
"b" => "second",
   
"c" => "something",
   
"red"
);

$array2 = array(
   
"a" => "first",
   
"b" => "something",
   
"letsc"
);

print_r(array_fill_keys($array1, $array2));
?>

The output will be
Array(
    [first] => Array(
        [a] => first,
        [b] => something,
        [0] => letsc
    ),
    [second] => Array(
        [a] => first,
        [b] => something,
        [0] => letsc
    ),
    [something] => Array(
        [a] => first,
        [b] => something,
        [0] => letsc
    ),
    [red] => Array(
        [a] => first,
        [b] => something,
        [0] => letsc
    )
)
up
2
Scratchy
16 years ago
RE: bananasims at hotmail dot com

I also needed a work around to not having a new version of PHP and wanting my own keys. bananasims code doesn't like having an array as the second parameter...

Here's a slightly modified version than can handle 2 arrays as inputs:

//we want these values to be keys
$arr1 = (0 => "abc", 1 => "def");
/we want these values to be values
$arr2 = (0 => 452, 1 => 128);

function array_fill_keys($keyArray, $valueArray) {
    if(is_array($keyArray)) {
        foreach($keyArray as $key => $value) {
            $filledArray[$value] = $valueArray[$key];
        }
    }
    return $filledArray;
}

array_fill_keys($arr1, $arr2);

returns:
abc => 452, def =>128
up
-4
bananasims at hotmail dot com
17 years ago
Some of the versions do not have this function.
I try to write it myself.
You may refer to my script below

function array_fill_keys($array, $values) {
    if(is_array($array)) {
        foreach($array as $key => $value) {
            $arraydisplay[$array[$key]] = $values;
        }
    }
    return $arraydisplay;
}
up
-8
matrebatre
16 years ago
This function does the same as:
<?php
$array
= array_combine($keys,array_fill(0,count($keys),$value));
?>
up
-5
phydeaux
16 years ago
Scratchy's version still doesn't work like the definition describes.  Here's one that can take a mixed variable as the second parameter, defaulting to an empty string if it's not specified.  Don't know if this is exactly how the function works in later versions but it's at least a lot closer.

function array_fill_keys($target, $value = '') {
    if(is_array($target)) {
        foreach($target as $key => $val) {
            $filledArray[$val] = is_array($value) ? $value[$key] : $value;
        }
    }
    return $filledArray;
}

This works for either strings or numerics, so if we have

$arr1 = array(0 => 'abc', 1 => 'def');
$arr2 = array(0 => 452, 1 => 128);
$arr3 = array(0 => 'foo', 1 => 'bar');

then

array_fill_keys($arr1,$arr2)
returns: [abc] => 452, [def] => 128

array_fill_keys($arr1,0)
returns: [abc] => 0, [def] => 0

array_fill_keys($arr2,$arr3)
returns: [452] => foo, [128] => bar

array_fill_keys($arr3,'BLAH')
returns: [foo] => BLAH, [bar] => BLAH

and array_fill_keys($arr1)
returns: [abc] =>, [def] =>
up
-6
ntd at entidi dot it
9 years ago
To remove arbitrary keys from an associative array:

<?php

function nuke_keys($keys, $array) {
    return
array_diff_key($array, array_fill_keys($keys, 0));
}

$array = array('blue'  => 1, 'red'  => 2, 'green'  => 3, 'purple' => 4);
$keys  = array('red', 'purple');

print_r(nuke_keys($keys, $array));
?>

The above snippet will return:

Array
(
    [blue] => 1
    [green] => 3
)
up
-4
manavchugh988 at gmail dot com
2 years ago
see array_fill_keys are basically used to make a new array from a pre-existing array in a form that the value of the pre-existing array will now be the key of the new Array .And there value will be same That we had given in the 2nd parameter . Example Below---->>>

<?php
       
//pre existing array
       
$a = array("a","b","c","d","e");

       
//new array with a single same value

       
$newArray = array_fill_keys($a, "Testing");

       
//printing the array

       
echo "<pre>";
       
print_r($newArray);
        echo
"</pre>";
?>
output;
    Array
(
    [a] => Testing
    [b] => Testing
    [c] => Testing
    [d] => Testing
    [e] => Testing
)
up
-21
taylanaktepe at yahoo dot com
10 years ago
$keys = array(1, 2, 3);

// Fill it with value.
$keys = array_fill_keys($keys, 'banana');
print_r($keys);

// Fill it different value.
$apples = array_fill_keys(array_keys($keys), 'apple');
print_r($apples);

// Output:
Array (
[1] => banana
[2] => banana
[3] => banana
)
Array (
[1] => apple
[2] => apple
[3] => apple
)
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