Question

Is it possible in PHP to specify a named optional parameter when calling a function/method, skipping the ones you don’t want to specify (like in python)?

Something like:

function foo($a, $b = '', $c = '') {
    // whatever
}


foo("hello", $c="bar"); // we want $b as the default, but specify $c

Answer 1

No, it is not possible (before PHP 8.0): if you want to pass the third parameter, you have to pass the second one. And named parameters are not possible either.

A “solution” would be to use only one parameter, an array, and always pass it… But don’t always define everything in it.

For instance :

function foo($params) {
    var_dump($params);
}

And calling it this way : (Key / value array)

foo([
    'a' => 'hello',
]);

foo([
    'a' => 'hello',
    'c' => 'glop',
]);

foo([
    'a' => 'hello',
    'test' => 'another one',
]);

Will get you this output :

array
  'a' => string 'hello' (length=5)

array
  'a' => string 'hello' (length=5)
  'c' => string 'glop' (length=4)

array
  'a' => string 'hello' (length=5)
  'test' => string 'another one' (length=11)

But I don’t really like this solution :

• You will lose the phpdoc
• Your IDE will not be able to provide any hint anymore… Which is bad

So I’d go with this only in very specific cases — for functions with lots of optional parameters, for instance…