PHP function building a default variables? [duplicate]

Question

I am trying to build a function that has 2 default values, but on some occasions I need to supply only the first argument, and others only the second. Is there a way in PHP that I can do this, or is there a way of doing what I want that is considered standard?

Example

function ex($a, $b = null, $c = null) {
    ....
}

ex($a, $b, $c) // WORKS FINE

ex($a) // WORKS FINE

ex($a, $b) // WORKS FINE

ex($a, $c) // WANT VAR C TO BE VAR C IN THE FUNCTION AND NOT VAR B

Thanks

Answer 1

ex($a, $c) // WANT VAR C TO BE VAR C IN THE FUNCTION AND NOT VAR B

Skip second param:

ex($a, null, $c);

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