What is PHP array_fill_keys() Function?
array_fill_keys() function creates an array filling keys from values of an array and filling values from a provided value or values of another array.
Syntax:
array_fill_keys(keys, value)
Parameters:
The Function has 2 parameters; both are required-
keys (Required): It is an array whose values the function uses as keys in the new array.
values (Required): It is a value (string, integer etc) or a list of values (array) that the function uses as values in the new array.
Return Values:
The function returns an array filled with provided array and value pair or array or array pair.
Examples:
Example 1:
<pre>
<?php
$keys = ['Physics', 'Chemistry', 'Math', 'Language'];
$value = 100;
$last_array = array_fill_keys($keys, $value);
print_r($last_array);
?>
</pre>
Output:
Array
(
[Physics] => 100
[Chemistry] => 100
[Math] => 100
[Language] => 100
)
Example 2:
<pre>
<?php
$keys = ['Physics', 'Chemistry', 'Language'];
$value = ['1st' => 100, '2nd' => 'N/A'];
$last_array = array_fill_keys($keys, $value);
print_r($last_array);
?>
</pre>
Output:
Array(
[Physics] => Array
(
[1st] => 100
[2nd] => N/A
)
[Chemistry] => Array
(
[1st] => 100
[2nd] => N/A
)
[Language] => Array
(
[1st] => 100
[2nd] => N/A
)
)
Practical Usages of array_fill_keys() Function:
This function is very useful when you want to quickly create an array filling with pre-defined keys and values.
Notes on array_fill_keys() Function:
- Illegal values for key will be converted to string.
PHP Version Support:
PHP 5 >= 5.2.0, PHP 7, PHP 8
Summary: PHP array_fill_keys() Function
If you want to create an array filling with pre-defined values for its keys and values, use array_fill_keys() function which is a built-in PHP array function.