[基础概念](%E5%9F%BA%E7%A1%80%E6%A6%82%E5%BF%B5.md) [三大特征](%E4%B8%89%E5%A4%A7%E7%89%B9%E5%BE%81.md) [9个常用的魔术方法](9%E4%B8%AA%E5%B8%B8%E7%94%A8%E7%9A%84%E9%AD%94%E6%9C%AF%E6%96%B9%E6%B3%95.md) [抽象类](%E6%8A%BD%E8%B1%A1%E7%B1%BB.md) [对象接口](%E5%AF%B9%E8%B1%A1%E6%8E%A5%E5%8F%A3.md)