[const关键字](const%E5%85%B3%E9%94%AE%E5%AD%97.md) [final关键字](final%E5%85%B3%E9%94%AE%E5%AD%97.md) [abstract用于定义抽象方法和抽象类。](abstract%E7%94%A8%E4%BA%8E%E5%AE%9A%E4%B9%89%E6%8A%BD%E8%B1%A1%E6%96%B9%E6%B3%95%E5%92%8C%E6%8A%BD%E8%B1%A1%E7%B1%BB%E3%80%82.md) [self、$this、parent::关键字](self%E3%80%81this%E3%80%81parent%E5%85%B3%E9%94%AE%E5%AD%97.md) [接口(interface)](%E6%8E%A5%E5%8F%A3(interface).md) [trait关键字](trait%E5%85%B3%E9%94%AE%E5%AD%97.md) [instanceof关键字](instanceof%E5%85%B3%E9%94%AE%E5%AD%97.md) [魔术方法](%E9%AD%94%E6%9C%AF%E6%96%B9%E6%B3%95.md)