Define optional argument for function

Yoosha · 06-15-2008, 02:26 PM

Hi,
How to define optional argument for function?

Salathe · 06-15-2008, 03:42 PM

PHP Code:


			
function myfunction($myarg = 'default')
{
    echo 'You specified, ', $myarg, '<br>';
}

myfunction('a custom value');
myfunction();

Orc · 06-15-2008, 04:14 PM

Quote:

Originally Posted by Salathe

PHP Code:


			
function myfunction($myarg = 'default')

{

    echo 'You specified, ', $myarg, '<br>';

}



myfunction('a custom value');

myfunction();

That would output a custom value on the first function return, and default on the second return.

Aaron · 06-15-2008, 08:23 PM

Why can't we just put optional parentheses in brackets like php.net?

myfunction(Taco,[$beans],[$rice])

mm I'm hungry now.

To answer your question
make it equal something in the function call like demonstrated above.

Code:

function myfunction($myarg = 'default')

If you specify a parameter, it will overrule what you put in for defaults.

Salathe · 06-15-2008, 09:10 PM

Quote:

Originally Posted by Aaron

Why can't we just put optional parentheses in brackets like php.net?

myfunction(Taco,[$beans],[$rice])

That's simply a notation style used by the PHP Manual, nothing to do with actual PHP code.

Aaron · 06-15-2008, 09:12 PM

Thats why I posted that.

delayedinsanity · 06-15-2008, 11:09 PM

Technically you could have an unlimited amount of optional arguments. The first way, and probably the least aesthetically pleasing would be to define a single argument and check if it's an array or not;

PHP Code:


			
function snuffleluffagus ($mArgs) {

    if (is_array($mArgs)) {
        $intNumArgs = count($mArgs);
        // ..
    } else {
        // ..
    }

}

..and the second would use PHP's built in functionality, with func_num_args() and func_get_args().

PHP Code:


			
// example borrowed directly from PHP.net

function foo () {

    $numargs = func_num_args();
    echo "Number of arguments: $numargs<br />\n";
    if ($numargs >= 2) {
        echo "Second argument is: " . func_get_arg(1) . "<br />\n";
    }
    $arg_list = func_get_args();
    for ($i = 0; $i < $numargs; $i++) {
        echo "Argument $i is: " . $arg_list[$i] . "<br />\n";
    }

}

-m

Folio · 06-16-2008, 09:05 AM

remember, you could set the arg to NULL - then if it exists when the function is called, the value will be set - if not, it will be NULL

function myFunction($arg = NULL) {}

Yoosha · 06-17-2008, 07:47 AM

This is right(I think):

myfunction($Taco, [$beans], [$rice])
...

xenon · 06-17-2008, 09:04 PM

Quote:

Originally Posted by Yoosha

This is right(I think):

myfunction($Taco, [$beans], [$rice])
...

That isn't even possible

not kewl man, not kewl

delayedinsanity · 06-17-2008, 09:08 PM

For real xenon.

PHP Code:


			
unset ($beans, $rice);
new Taco ($hamburger, $tomato, $sourcream) or die("go home");

-m

drewbee · 06-24-2008, 05:07 PM

PHP Code:


			
class Burrito extends Taco
{
     var $wrap_shell;
     var $butter;
     var $steak;
     var $cheese;
     var $ingrediants = array();
     var $burrito;
     function Burrito()
     {
         parent::__construct();
         $this->ingredients[] = $this->wrap_shell;;
         $this->ingredients[] = $this->butter;
         $this->ingredients[] = $this->steak;
         $this->ingredients[] = $this->cheese;
     }
 
     function stealTheGoods()
     {
         unset($this->hamburger);
         $this->ingredients[] = $this->tomato;
         $this->ingredients[] = $this->sourcream;
 
         
     }
     function makeBurrito()
     {
          $this->burrito = implode('()', $this->ingredients);
     }
 
     function eat()
     {
          if (!empty($this->burrito))
          {
              echo "This burrito is delicious!";
          }
          else
          {
              echo "The burrito has not been made yet :(";
          }
     }
}

Hmm... I always wondered how to uselessly waste 5 minutes... lol.

Yoosha · 06-25-2008, 05:37 AM

Define optional argument for function...

No other...

drewbee · 06-25-2008, 01:22 PM

lol Hey Yoosha, we kinda went a little crazy with your thread and the taco thing.

The first few posts of this thread correctly show how to do that though.

Do you still have questions about this?