Question

I have a class:

class Foo {
    // Accept an assoc array and appends its indexes to the object as property
    public function extend($values){
        foreach($values as $var=>$value){
            if(!isset($this->$var))
                $this->$var = $value;
        }
    }
}

$Foo = new Foo;
$Foo->extend(array('name' => 'Bee'));

Now the $Foo object has a public name property with value Bee.

How to change extend function to make variables private ?

Edit
Using a private array is another way and definitely not my answer.

Answer 1

Just plain, bad design.

What’s the purpose of adding a private [!] field at runtime? Existent methods can’t rely on such added fields, and you’d be messing with the object functionality.

If you want your object to behave like an hashmap [i.e. you can just call $obj -> newField = $newValue], consider using magic __get and __set methods.