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Solved

know to go back to DocumentObject::getGroup

Posted on 2014-04-23
5
177 Views
Last Modified: 2014-04-28
<?php
abstract class DomainObject {
    private $group;
    public function __construct() {
        $this->group = static::getGroup();
    }

    public static function create() {
        return new static();        
    }

    static function getGroup() {
        return "from default"; 
    }
}

class User extends DomainObject {
}

class Document extends DomainObject {
    static function getGroup() {
        return "from document"; 
    }
}

class SpreadSheet extends Document {
}
echo'<pre>';
$userCreate=User::create();
print_r($userCreate);
$spreadSheetCreate=SpreadSheet::create();
print_r($spreadSheetCreate);
echo'</pre>';
?>

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how does
$spreadSheetCreate=SpreadSheet::create();
know to go back to
DocumentObject::getGroup
0
Comment
Question by:rgb192
  • 2
  • 2
5 Comments
 
LVL 34

Accepted Solution

by:
Dan Craciun earned 250 total points
ID: 40019238
Through inheritance. The Spreadsheet class inherits Document's methods.
This includes the getGroup() method (which is overriden in the Document class).

HTH,
Dan
0
 
LVL 109

Expert Comment

by:Ray Paseur
ID: 40019814
For better or worse, computer programming is a "precise science" requiring that we use the right names for variables and functions.No such method
0
 

Author Comment

by:rgb192
ID: 40021859
sorry I meant
DomainObject::getGroup
not
DocumentObject::getGroup



go to different getGroup
$userCreate=User::create();
$spreadSheetCreate=SpreadSheet::create();

Through inheritance. The Spreadsheet class inherits Document's methods.
This includes the getGroup() method (which is overriden in the Document class).

Is this example of late static binding?
0
 
LVL 109

Assisted Solution

by:Ray Paseur
Ray Paseur earned 250 total points
ID: 40022403
Late Static Binding is a bit different from Inheritance.  If you read these two man pages carefully and find yourself wondering about how a programmer can keep track of what software is being executed, you're not alone.  Mercifully, PHP did not introduce multiple inheritance!

I have a shovel and a rake.  If I really try, I can gather leaves with the shovel and dig a hole with the rake.  But doing either would be a "run-time error."  That is kind of how I think of some of the more arcane programming constructs.  The simpler and more obvious I can make my code, the more likely I will finish the task quickly and accurately.
0
 

Author Closing Comment

by:rgb192
ID: 40028773
thanks for examples about calling methods.
0

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