// our main class becomes a file but the main method is still found

publicclass HelloWorld

{

  publicstaticvoid main(String[] args)

  {

        Animal puppy1 =new Animal(6,70);

        puppy1.speak();

        Animal puppy2 =new Animal(142);

        puppy2.speak();

        Animal puppy3 =new Animal();

        puppy3.speak();

  }

}

class Animal {

    privateint age;

    privateint weight;

    public Animal(int a,int w){

        setAge(a);

        setWeight(w);

        System.out.println("2 parameters of the constructor,Animal's object created....");

    }

    public Animal(int w){

        setAge(3);

        setWeight(w);

        System.out.println("1 parameter of the constructor,Animal's object created....");

    }

    public Animal(){

        setAge(3);

        setWeight(15);

        System.out.println("Animal's object created....");

    }

    publicint getAge(){

        return age;

    }

    publicvoid setAge(int n){

        if(n <0){

            age =1;

        }

        else{

            age = n;

        }

    }

    publicint getWeight(){

        return weight;

    }

    publicvoid setWeight(int n){

        if(n <0){

            weight =1;

        }

        else{

            weight = n;

        }

    }

    publicvoid speak(){

        System.out.println("Hello,I am "+ getAge()+" years old. I weighed "+ getWeight()+" kg");

    }

}