Question

I have two classes Foo and Bar that Bar extends Foo as below:

class Foo {
    protected 
        $options = array(), 
        $defaults = array(1, 2);

    public function __construct($options){
        array_push($this->options, $this->defaults);
    }
}

class Bar extends Foo {
    protected $defaults = array(3, 4);

    public function print(){
        print_r($this->$options);
    }
}

$bar = new Bar();
$bar->print();

i thought that result should be array(1,2,3,4) but is array(3,4).
how to solve that ?

edit
i don’t want Bar class to have constructor because i’m just implementer of superclass and don’t know what really will happen in child class.

Answer 1

There are a couple of solutions, the simplest would be a second variable to be used as an extended defaults, then merge the arrays.

class Foo {
    protected
        $options = array(),
        $original_defaults = array(1, 2),
        $extended_defaults = array();

    public function __construct($options){
        array_merge($this->extended_defaults, $this->original_defaults);
        array_push($this->options, $this->original_defaults);
    }
}

class Bar extends Foo {
    protected $extended_defaults = array(3, 4);

    public function print(){
        print_r($this->$options);
    }
}

$bar = new Bar();
$bar->print();