any way to iterate the fields in a class

Actually, what I am seeking is how to assign values to the fields in a class via an array. I have tried like this. However failed. I have a class. *class book{ var name;* *var price;* *}* * * And I have got an array. *$array=array('name'=>'harry potter','price'=>'$122');* By using function *extract(), *I assign the values to $name and $price while not $this->name and $this->price, which is not what I want. So I am thinking iterating the fields in an array and assign the values each by each through an array. Is there any way to assign values to the fields in a class via an array. Thanks in advance!