array_fill_keys : Creats array by filling value with values of of an input array as keys

Current PHP usage

array_fill_keys() creates a new array whose keys come from the values of another array. Every generated key receives the same value.

$fields = ['name', 'email', 'phone'];
$defaults = array_fill_keys($fields, '');
print_r($defaults);

This is useful for defaults, placeholders and lookup structures when the same initial value applies to every key.

$new_array = array_fill_keys ($keys_array, $value);

$keys_array : An array whoes values will be used as keys.

$value: This will be used as filling ( the value of the output array )

Output will be a new array with filled keys and value.

Example with two arrays

$keys=array('One' ,'Two','Three','Four');
$input='First';

$result=array_fill_keys($keys,$input);
foreach ($result as $key => $val) {
echo "$key -> $val <br>";
}

Output is here.

One -> First 
Two -> First 
Three -> First 
Four -> First

Example 2

$keys=array('One' ,2,'3','F');
$input='First';

$result=array_fill_keys($keys,$input);
foreach ($result as $key => $val) {
echo "$key -> $val <br>";
}

Output

One -> First 
2 -> First 
3 -> First 
F -> First

Example 3 : Using associative array

$keys=array('One' ,'Two','Three');
$input=array('First','Second');
$result=array_fill_keys($keys,$input);
print_r($result);

Output

Array ( 
  [One] => Array ( [0] => First [1] => Second )
  [Two] => Array ( [0] => First [1] => Second )
  [Three] => Array ( [0] => First [1] => Second )
  )

Example 4: Initializing a Configuration Array

$config_keys = ['timezone', 'language', 'currency'];
$default_values = array_fill_keys($config_keys, 'default_value');
print_r($default_values);
// Output: Array ( [timezone] => default_value [language] => default_value [currency] => default_value )

Example 5: Placeholder Array with Empty Values

$keys = ['name', 'email', 'phone'];
$placeholders = array_fill_keys($keys, '');
print_r($placeholders);
// Output: Array ( [name] => [email] => [phone] => )

Example 6: Generating a Grid with Default Values

$grid_keys = range(1, 100);
$grid = array_fill_keys($grid_keys, 0);
print_r($grid);
// Output: Array ( [1] => 0 [2] => 0 ... [100] => 0 )

Returns the First Key Creating array
Array REFERENCE

Subhendu Mohapatra

Author & Instructor at plus2net

I write and maintain practical tutorials on Python, PHP, SQL, JavaScript, HTML, jQuery, and web development at plus2net. The tutorials focus on clear explanations, working examples, and code that readers can test and adapt while learning.

About the author Watch on YouTube

Connect: