如何在函数中定义变量并在类中使用

Question

我想通过函数在类中创建新变量：

CLASS book{

   public function set($name){
      newvar($name);
   }
}

function newvar($str){
   ***????
   /// what is code for here***
}

例子：

$x = new BOOK();
$x->set('title');

$x->title = 'jack';
echo 'book title is: ' . $x->title;

echo '<br>-----------------------------<br>';

$x->set('writer');
$x->writer = 'tom';
echo 'book writer is: ' . $x->writer;

结果：

book title is jack;
----------------------------------
book writer is tom;

Answer 1

它是 php :)

CLASS book{
   public function set($name){
      $this->$name = null;
   }
}

甚至可以使用下面的代码动态添加属性

$x = new book();
$x->writer = 'tom';

演示