Array destructuring assignement with optional values - php

Question

Is there any solution in PHP to make an array destructuring assignment with associative keys can extract optional values/default values (like the example below)?
Because when I tried, I always get undefined index 'age' (it's because it is not set).
See example:
// implementation
function myFunction(array $params = ['name' => 'user-name', 'age' => 15]){
['name' => $name, 'age' => $age ] = $params;
echo $name.' '.$age;
}
// Execution:
// normal case
myFunction(['name' => 'user', 'age' => 100]);
// Output: user 100
// Wanted case to be released
myFunction(['name' => 'user']);
// Output: user 15 <== i want to get this default age value if i don't set it in the given associative array params.

Answer 1

What about defining an array with default values?
function myFunc(array $params, array $defaults = [ 'name' => 'Marcel', 'age' => 40 ]): string
{
$data = array_merge($defaults, $params);
[
'name' => $name,
'age' => $age
] = $data;
return $name . $age;
}
The array merge overwrites the default values with the given param values. So the return will always be a complete mixture of both values. If you send a name only, the name will be mixed up with the default age. If you give an age only, the age will be mixed up with the default value.
myFunc([ 'name' => 'sohaieb', 'age' => 15 ]); // => sohaieb15
myFunc([ 'name' => 'yadda' ]); // => yadda40
The second parameter $defaults can be changed, if the defaults change in the future. A possible scenario: You set the default values in a config. With this solution the function can take the default settings from the config and don 't has to be touched in the future.

Answer 2

Well, since you pass in a parameter, it will always take that instead of the default one. However, you can use the union operator + to merge it with default values if not present in the originally supplied value during function call.
<?php
function myFunction(array $params = []){
$params = $params + ['name' => 'user-name', 'age' => 15];
['name' => $name, 'age' => $age ] = $params;
echo $name.' '.$age;
}
myFunction(['name' => 'user']);

Answer 3

Because $params is an array, so it overrides the default values even if you pass in an empty array.
One way to do this is to check the value inside your function body.
function myFunction(array $params){
$name = $params['name'] ?? 'user-name';
$age = $params['age'] ?? 15;
echo $name.' '.$age;
}
// Execution:
// normal case
myFunction(['name' => 'user', 'age' => 100]);
// Output: user 100
// Wanted case to be released
myFunction(['name' => 'user']);
Reference
https://wiki.php.net/rfc/isset_ternary