array_fill_keys()

(PHP 5 >= 5.2.0, PHP 7)

使用指定的键和值填充数组

说明

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

使用$value参数的值作为值，使用$keys数组的值作为键来填充一个数组。

参数

$keys

使用该数组的值作为键。非法值将被转换为字符串。

$value

填充使用的值。

返回值

返回填充后的数组。

范例

Example #1array_fill_keys()范例

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

以上例程会输出：

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

参见

• array_fill() 用给定的值填充数组
• array_combine() 创建一个数组，用一个数组的值作为其键名，另一个数组的值作为其值

<?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.

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
  )
)

This function does the same as:
<?php
$array = array_combine($keys,array_fill(0,count($keys),$value));
?>

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

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] =>

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;
}

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
)

$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
)