Opptional Arguments Defining Functions

[As5a5sIn5]

Now Im turning into a guy who makes a lot of functions and classes and I've stumbled upon errors when leaving so of my own function arg's blank....now I know all the predefined functions make arg's opptional, so how can I make my function arg's opptional and I'm making them in classes so inc. that...


Thanks In Advance

[firepages]

note that you can't have optional args passed by reference so you can't do &$optional_arg='' etc otherwise ...

PHP Code:

<?
function blah( $arg1 , $optional_arg='' , $optional_arg2='' ){
  if( !empty( $optional_arg ) ){
     //do_stuff//
  }
}
blah( 'yaks' ) ;
blah( 'yaks' , 'yaks' ) ;
blah( 'yaks' , '' , 'yaks' ) ;
?>

this can get confusing sometimes so I like to use null when not passing an arg (so all calls at least look the same)
blah( 'yaks' , null , 'yaks') ;
but then you should be checking for is_null() within your function

And some will say the above is bad juju , perhaps thats true , I am now in the habit of passing a optional array of data instead , this makes things far easier to refactor if you need to another argument to a common function at some future point and do not want to trawl your code changing function calls to do so

PHP Code:

<?
$optional_args = array('arg2'=>'blah','arg3'=>'blah') ;
blah('yaks' , $optional_args ) ;
?>

[Hawkmoon]

Firepages second example is the same thing I use and it really works great. It makes adding args to class methods very easy plus you can do things like this:

PHP Code:


class objSQL() {

  function edit($table,$values) {   //$values could equal $_POST or some other Global array
    $sql  = "UPDATE $table ";
    $sql .= " SET";
    foreach($values as $key=>$value) {
      ${$key} = htmlentities($value);
      $sql .= "    $key='" . ${$key} . "',";
    }
    $sql = substr( $sql,0,(strlen($sql)-1) ); //Remove the last comma
    $sql .= "    WHERE {$this->unique}='". $this->uniquid . "'";  //Primary Key

    return $this->query($sql);
  }

}