5 replies to this topic

[rhossis]

Hi,

I am implementing an abstract class in PHP with some properties in the base class. How do I ensure that these will all this be carried down to children that extend the class?

Regards,
Cyril

[ghost_x47]

You just need to extend a class... that's all,
if you do something in construcor method of abstract class - you probably need to call it in childs constructor as or something like that -

parent::__construct(args);

Also if you want to be oversure - then you might do some variables checking)

[sam_l]

That is how inheritance works.

class A 

{

  protected var $a;

}


class B extends A

{

  public void nonsensicle()

  {

    $this->a = 10;

    echo $this->a;

  }

}

[ghost_x47]

This also should work, and for syntax - there is no 'var' after protected...
thanks,I forgot about that)

• public - can be enherited;
  
• protected - can be enherited;
  
• private - can NOT be enherited

class A 

{

  protected $a = 10;

}


class B extends A

{

  public void nonsensicle()

  {

    echo $this->a;

  }

}

[rhossis]

Thanks, I was not aware of the fact that the abstract class could have some features declared in it and inherited.

[Orjan]

Abstract can have as much or as little as you want declared, you can even have a full declaration. if you just declare it abstract, the only thing is that you can't instantiate from it, it needs to be inherited first.