Inheritance is mean "extending" a class. When we extend a class, we use extends keyword. It will add methods and properties in new class from base class. For example like following code:
<?
class vehicle
{
var $type;
var $limit = 100;
function vehicle( $type )
{
$this->type = $type;
}
function oil_change ( $miles )
{
return ($miles / $this->limit);
}
}
class car extends vehicle
{
var $limit = 1500;
function car ( $type )
{
$this->type = $type;
}
}
$obj = new car( 'city car' );
echo $obj->type;
echo $obj->oil_change(4500);
?>
