PHP仅在许多默认值中提供一个特定参数

<?php

class klasa {
    public function funkcja($x = 'default', $y = 'value')
    {
        var_dump($x);
        var_dump($y);
    }
}

$x = new klasa;
$x->funkcja('other value');

As on the picture, how to omit first parameter which has his default value and only affect second one?

I tried $x->funkcja(NULL, 'other value'); doesn't work, $x->funkcja(, 'other value'); doesn't work too.

How to achieve it?

One of the possible answers. Basically, check if value is null and then assign a default value.

class klasa {
    public function funkcja($x, $y = 'value')
    {
        $x = ($x === null ? 'default' : $x);

        var_dump($x);
        var_dump($y);
    }
}

$x = new klasa;
$x->funkcja(null, 'value');

$x === null - Check if $x is null
?
'default' - If it's true assign a default value
:
$x - If it's not true reassign it's value