I am trying to create a standard function that I can use to create text boxes but some times I need more variable then others.

Two questions
1. Is there a limit to the number of variables that can be passed to a function?
2. When you look at the standard library of functions that come with PHP, the have optional values, how can I make values optional?

PHP Code:

textbox_list("Project","input","project",$row['project'],45,45,$tab++) 


PHP Code:

//Creates standard textbox
function textbox_list($label,$type,$name,$value,$maxlength,$size,$tab_index){
 $id=str_replace(" ","_",strtolower($label));
 if($type!='hidden') $string='<li><label for="'.$id.'">'.$label.':</label>';
 else    $string='<li>'; 
 $string.='<input class="text" id="'.$id.'" type="'.$type.'" name="'.$name.'" value="'.$value.'"';
 if (!empty($maxlength)) $string.=' maxlength="'.$maxlength.'"';
 if (!empty($size)) $string.=' size="'.$size.'"';
 if (!empty($tab_index)) $string.=' tabindex="'.$tab_index.'"'; 
 $string.=' /></li>';
 return $string;
} 


1. I can't say for sure, but there probably is a limit. I'm certain, however, that the limit is higher than the number of parameters you would realistically pass to a function.

2. There are two ways to approach this. You can use default values:

PHP Code:

function add($a, $b, $c = 5)
{
     return $a + $b + $c;
}

echo add(1, 1); //will output 7 


or you can dynamically retrieve parameters using func_get_args:

PHP Code:

function add()
{
    $total = 0;
    $args = func_get_args();

    foreach($args as $arg)
    {
        if(is_numeric($arg))
            $total += $arg;
    }
    return $total;
}

echo add(1, 2, 3); //will output 6 


Is there a limit to the number of variables that can be passed to a function?

Probably, but you could avoid it if ever by passing 1 argument that would be an array or an object.

I often use an object as a return, when I need more than one info given back.
Like a status (true/false) with a explanation (for a login, for example).
Simple to extend to your taste

Originally Posted by tripy

I often use an object as a return, when I need more than one info given back.
Like a status (true/false) with a explanation (for a login, for example).
Simple to extend to your taste

I do this as well when I need several pieces of information from a function. If I only need one or two, however, I usually use references:

PHP Code:

function login(&$err)
{
     /*
     .
     .
     */
     $err = 'Invalid username/password';
     return false;
}

if(!login($errorMessage))
     echo $errorMessage;