Optional Arguments in a Function

[RPMiSO]

How can I create optional arguments?

 

Lets say I have:

function getPost($id,$category,$username){
//some code to execute
}

 

Now when I call getPost with just $id I'm going to get some warnings about missing arguments. How can I get around this?

[roopurt18]

function getPost($id,$category,$username = 'foo'){
//some code to execute
}