小编Dus*_*rza的帖子

我试图声明一个变量,特别是$ publisher变量,但它不起作用.我不确定我是否正确地扩展了课程.

书籍是主要的类,而Novel是扩展类.

PHP课程

class Books {

    /* Member variables */
    public $price;
    public $title;

    /* Member functions */
    public function setPrice($par){
        $this->price = $par;    
    }

    public function getPrice(){
        echo $this->price.'<br/>';
    }

    public function setTitle($par){
        $this->title = $par;
    }

    public function getTitle(){
        echo $this->title.'<br/>';
    }

    public function __construct($par1,$par2){
        $this->title = $par1;
        $this->price = $par2;
    }

}

class Novel extends Books {
    public  $publisher;

    public function setPublisher($par){
        $this->publisher = $par;
    }

    public function getPublisher(){
        echo $this->publisher; …