Using Abstract Classes and Methods : Abstract Class « Class « PHP

1. PHP
2. Class
3. Abstract Class

Using Abstract Classes and Methods

 
Any class that contains one or more abstract methods must itself be declared as abstract. 
An abstract class cannot be instantiated
A class that extends the abstract class must implement the abstract methods of the parent class or itself be declared as abstract. 

<?
abstract class Animal{ 
    function __construct($name='No-name', $breed='unknown', $price = 15) { 
        $this->name = $name; 
        $this->breed = $breed; 
        $this->price = $price; 
    } 
    function setName($name) { 
        $this->name = $name; 
    } 
    function setBreed($breed){ 
        $this->breed = $breed; 
    } 
    function setPrice($price) { 
        $this->price = $price < 0 ? 0 : $price; 
    } 
    function getName() { 
        return $this->name; 
    } 

    function display() { 
        printf("<p>%s is a %s and costs \$%.2f.</p>\n", $this->name, $this->breed, $this->price); 
    } 
    public static $type = "animal"; 
    
    public static function fly($direction = 'around') { 
        printf("<p>Flying %s.</p>\n", $direction); 
    } 
    abstract public function birdCall(); 
    
} 


class Parrot extends Animal { 
    public function birdCall($singing=FALSE) { 
        $sound = $singing ? "twitter" : "chirp"; 
        printf("<p>%s says: *%s*</p>\n", $this->getName(), $sound); 
    }
}
?>
  
  

Related examples in the same category