inherit variable from object

[martijn1967_1]

Hello

I thought php could inherit from a main class. Some way the variable in the subclass seems to be empty.

<?php
class Animals
{
var $Legs;
function Animals()
{
$this->Legs = 4;
}
}

class Dogs extends Animals
{
function Dogs()
{

}
}

$data = new Animals;
$data->Legs = 8;

$Dog = new Dogs;
$Number = $Dog->Legs;

echo"Legs: $Number\n";

?>

Can someone explain to me why i can't inherit a variable from the main class? I know it can be done by define(), but is there another possibility?

[eoghain]

You can and do inherit the variable $legs from the parent class, but if the variable isn't set, or the parent class constructor isn't called then get nothing. And remeber that an object is completely different from a class, just cause you instantiate an object of type Animal doesn't mean that all derrived classes of Animal will now get the values of your new Animal object. Here is how you could write these classes to make them behave the way you expect:

<?php
   class Animals { 
      var $Legs; 

  function Animals()  { 
     $this->Legs = 4;   // Set default number of legs
  } 
   } 

   class Dogs extends Animals { 
      function Dogs() { 
         parent::Animals();  // Call parents constructor
      } 
   } 

   $data = new Animals; 
   $data->Legs = 8; 

   $Dog = new Dogs; 
   $Number = $Dog->Legs; 

   echo"Legs: $Number\n";   // Should print 4
?>

[martijn1967_1]

thnx, thats what i needed