What's the scope of this?

dotwebbie

Don't go 'splainin' what scope is, I've coded in both C++ and Java, other than PHP, Javascript, some Perl, yada yada yada. So I have a pretty good idea what scope is. 😛

First off, if this belongs in Coding, please move it. I couldn't decide where this topic belonged, so ...

Okay, here is my question. What is the scope of a variable in a class? More specifically, what is the scope in the extension of the class? For example:

class HiWorld
{
         $blah, functions, vars, etc.
}

class ByeWorld extends hiWorld
{
        echo($blah);
}

So ... What do I have to do? If you guys want to see the specific code I'm talking about, I can link you.

planetsim

Well firstly it should be defined as an object in the main class.

So e.g.


class myClassOne {
  function ObjectOne() {
    $blah='blah';
  }
}

class myExtend extends myClassOne {
  function outPutVar() {
    echo $blah;
  }
}

That wont work as its not an object but if we had another function(object) within the main class myClassOne it still wouldnt be accessible for obvious reasons i hope.

PHP 5 i think changes a little how an object variable is accessible within an extension of a class im not 100% sure as i havent really ventured into it yet. Im sure someone will correct me on this matter.

However in PHP 4 it works like below:

class myClassOne {
var $blah; //creates object blah
  function ObjectOne() {
    $this->blah='blah';
  }
}

class myExtend extends myClassOne {
  function outPutVar() {
    echo $this->blah;//outputs blah
  }
}

Not sure if that helps/makes sense/or even what you wanted

dotwebbie

Yeah, I think that is pretty much what I wanted. Thanks. 🙂

If it helps you any, here is my code: (Yes, I know it needs cleaning up)

http://dev.site-control.org/trunk/web/modules/core/serverstatus_admin.php

Maybe that will help you understand what I am trying to accomplish. The main stuff for phpSysInfo will be in the class Server. I will also setup my template stuff and so on there. My extended classes (I may be adding more/removing some) will hold their various stuff.

Actually, my fault, I said backwards above, I want to access an extended class from a main class. And possibly vice versa. I thought I had it all worked out in my head, but the more I think about it, the more I think I didn't have it worked out. 🙁 Thank you again for your help. 🙂

planetsim

Well the extended class will always be able to access the main class as its basically all copied over into the extended class (object variables and functions). However accessing the extended class from within the main is not possible unless its initiated in the main class which i think defeats the purpose of having the class extended.

You may get better insight at the manual as well i havent actually read a great deal about extends in it also the user comments im sure would be helpful