JAVA Program for Addition and substraction using object

Objective: JAVA Program for Addition and substraction using object

Code : 

class java9 {

    int a = 10;

    int b = 20;

    public int add() {

        return (a + b);

    }

    public int sub() {

        return (a - b);

    }

}

class test {

    public static void main(String args[]) {

        java9 x1 = new java9();

        java9 x2 = new java9();

        int p = x1.add();

        int q = x2.sub();

        System.out.println("add: " + p);ja

        System.out.println("sub: " + q);

    }

}

Output :