Passing an optional parameter in PHP Function [duplicate]

Question

How can I pass an optional parameter to a PHP function. For example

function test($required, $optional){..} 

So that i should be able to call the function by passing either one parameter or both. For example:

test($required, $optional) test($required); 

Thanks.

Answer 1

try this:

function test($required, $optional = NULL){..}  

then you can call

test($required, $optional) 

and with $optional null

test($required);   

Answer 2

With a default value:

function test($required, $optional="default value"){..}