现实世界中面向对象的思维

1.现实世界中的对象：状态和行为

对象：电动车

状态：扭油门 没扭油门

行为：加速 减速
2.根据对象编写类

class Electric vehicle {

      int accelerator = 0;

       int speed = 0;

       int gear = 1;

      void change accelerator(int newValue) {

         accelerator = newValue;

      }

      void change gear(int nweValue) {

         gear = newValue;

      }

      void speedUp(int increment) {

         speed = speed + increment;

      }

      void applyBrakes(int decrement) {

         speed = speed - decrement;

      }

      void printStates() {

         System.out.println("accelerator:" + accelerator + " speed:" + speed + " gear:" + gear);

      }

}