​x
 
<!DOCTYPE html>
<html>
<body>
​
<?php
class Fruit {
  public $name;
  public $color;
  public function __construct($name, $color) {
    $this->name = $name;
    $this->color = $color; 
  }
  public function intro() {
    echo "水果是 {$this->name}，颜色是 {$this->color}。"; 
  }
}
​
class Strawberry extends Fruit {
  public $weight;
  public function __construct($name, $color, $weight) {
    $this->name = $name;
    $this->color = $color;
    $this->weight = $weight; 
  }
  public function intro() {
    echo "水果是 {$this->name}，颜色是 {$this->color}，重量是 {$this->weight} 克。"; 
  }
}
​
$strawberry = new Strawberry("草莓", "红色", 50);
$strawberry->intro();
?>
 
</body>
</html>