[RESOLVED] Question About Functions' Default Values

[trevorsg]

Hi,

I need to write a function that has conditional default values. For example:

function myFunction($arg1, $arg2=false, $arg3 ??)

If possible, I need to make $arg3 REQUIRED if and only IF $arg2=true.
Then this particular function would only be able to be called with 1 or 3 arguments, but not 2. For example, I could call it thusly:

myFunction(35); //only uses first argument
myFunction(35, true, 'G'); //uses all
//the following would be illegal:
myFunction(35, true);

I suppose the function signature would look like this:
myFunction( int $arg1 [, boolean $arg2, string $arg3] )
Does this make sense? Thanks for any help.

[laserlight]

There are a few ways to handle this, but to decide which is best, we need to know the context of this function (i.e., what does it do, what do the arguments mean, etc).

For example, does the third argument have any meaning in the code below?

myFunction(35, false, 'G');

[NogDog]

You could do:

function myFunction($arg1, $arg2=false, $arg3=null)
{
   if($arg2 == true and $arg3 === null)
   {
      user_error(__FUNCTION__ . ': arg3 is required if arg2 is true');
      return(false);  // or throw exception if that is preferred 
   }
   // rest of function...
}

[trevorsg]

NogDog's solution works. Thanks.