instanceof操作符

　　　　　　　　　　　　　　　　　　instanceof操作符

instanceof操作符号是干什么的呢？

　　判断对象与类的关系，像DNA鉴定一样。

class Car {
    public void run() {
        System.out.println("car running");
    }
}

class Bus extends Car {
    public static void main(String[] args) {
        Bus b = new Bus();
    }
}

class Test {
    public static void main(String[] args) {
        Car car = new Car();
        Bus bus = new Bus();
        
        if(car instanceof Car) {
            System.out.println("car is Car's instance");
        }
        if(bus instanceof Bus) {
            System.out.println("bus is Bus's instance");
        }
        if(bus instanceof Car) {
            System.out.println("bus is Car's instance");
        }

        if(car instanceof Bus) {
            System.out.println("car is Car's instance");
        }else {
            System.out.println("car isn't Bus's instance");
        }

        Car c = new Car();
        Bus b  = new Bus();
        c = b; // 将Bus对象的引用赋值给变量c

        if(b instanceof Bus) {
            System.out.println("b is Bus's instance");
        }

        if(c instanceof Bus) {
            System.out.println("c is Bus's instance");
        }

        if(b instanceof Car) {
            System.out.println("b is Car's instance");
        }
    }
}