无参构造oppdemo3

public class Pet {

    public String name;
    public int age;

    //无参构造
    public  void shout(){
        System.out.println("叫了一声");
    }
}

public class Application {
    public static void main(String[] args) {

        Pet dog = new Pet();
        dog.name = "旺财";
        dog.age = 5;
        dog.shout();
        System.out.println(dog.name);
        System.out.println(dog.age);

        Pet cat = new Pet();

    }
}