Java36----instanceof和类型转换

public class Student extends Person{
    public void go(){
        System.out.println("go");
    }

}

/*
                //Object>String
                //Object>Person>Teacher
                //Object>Person>Student


                Object object = new Student();

                // System.out.println("X instanceof Y");//能不能编译通过

                System.out.println(object instanceof Student);//true
                System.out.println(object instanceof Person);//true
                System.out.println(object instanceof Object);//true
                System.out.println(object instanceof Teacher);//false
                System.out.println(object instanceof String);//false
                System.out.println("========================");
                Person person = new Student();
                System.out.println(person instanceof Student);//true
                System.out.println(person instanceof Person);//true
                System.out.println(person instanceof Object);//true
                System.out.println(person instanceof Teacher);//false
                //System.out.println(person instanceof String);//编译错误
                System.out.println("========================");
                Student student= new Student();
                System.out.println(student instanceof Student);//true
                System.out.println(student instanceof Person);//true
                System.out.println(student instanceof Object);//true
               // System.out.println(student instanceof Teacher);//编译错误
               // System.out.println(student instanceof String);//编译错误
 */

public class Application {
        public static void main(String[] args) {
             //类型之间的转换 ： 父     子

                //子类转换父类，可能丢失自己本来的一些方法！
               Student student = new Student();
               student.go();
               Person person = student;
        }
}

/*
1.父类引用指向子类的对象
2.把子类转换为父类，向上转至；
3.把父类转换为子类，向下转至； 强制转换
4.方便方法的调用，减少重复的代码！
 */

在这里插入代码片