public class Demo01 {

    public static void main(String[] args) {
        //Object>String
        //Object>Person>Teacher
        //Object>Person>Student
        Object o1 = new Student();
        System.out.println(o1 instanceof Student);//True
        System.out.println(o1 instanceof Person);//True
        System.out.println(o1 instanceof Object);//True
        System.out.println(o1 instanceof Teacher);//False
        System.out.println(o1 instanceof String);//False
        System.out.println("===========================");
        Person p = new Student();
        System.out.println(p instanceof Student);//True
        System.out.println(p instanceof Person);//True
        System.out.println(p instanceof Object);//True
        System.out.println(p instanceof Teacher);//False
        //System.out.println(p instanceof String);//编译报错,有继承关系才会编译通过
        System.out.println("===========================");
        Student s = new Student();
        System.out.println(s instanceof Student);//True
        System.out.println(s instanceof Person);//True
        System.out.println(s instanceof Object);//True
        //System.out.println(s instanceof Teacher);//编译报错
        //System.out.println(s instanceof String);//编译报错



    }

}

public static void main(String[] args) {
        int a = 1;
        int b = 0;
        try{//监控区域
            System.out.println(a / b);
        }catch (ArithmeticException e){//有异常才会执行
            System.out.println("程序出现异常，变量b不能为0");
        }finally {//无论有没有异常都会执行，善后工作，可以不写
            System.out.println("finally");
        }

    }

if(b == 0){//主动的抛出异常
                throw new ArithmeticException();
            }

 public void fun(int a,int b){
        if(b == 0){//主动的抛出异常
            throw new ArithmeticException();//一般用在方法中
        }
        System.out.println(a / b);
    }

public static void main(String[] args) {

        try {
            new Demo01().fun(1,0);
        } catch (ArithmeticException e) {
            e.printStackTrace();
        }

    }


    //假设这个方法中处理不了这个异常，可以方法上抛出异常
    public void fun(int a,int b)throws ArithmeticException{
        if(b == 0){//主动的抛出异常
            throw new ArithmeticException();//一般用在方法中
        }
    }

package 异常.Demo01;

public class Test {

    //可能会存在异常的方法

    static void test(int a) throws MyException {

        System.out.println("传递的参数为：" + a);

        if (a > 10){
            throw new MyException(a);//抛出
        }
        System.out.println("ok！");
    }

    public static void main(String[] args) {
        try {
            test(110);
        } catch (MyException e) {
            System.out.println("MyException->" + e);
        }
    }

}

package 异常.Demo01;

public class MyException extends Exception{

    //传递数字>10抛出异常
    private int detail;

    public MyException(int detaila){
        this.detail = detaila;
    }

    //toString:异常的打印信息
    @Override
    public String toString() {
        return "MyException{" +
                "detail=" + detail +
                '}';
    }
}