创建person类对象，使用，对象名，属性名，进行赋值，输出各个属性值

public class Main {
    public static void main(String[] args) {
        Person p = new Person();
        p.setA(12);
        System.out.println(p.getA());
    }



}

class Person {
    private int a;

    public Person() {
    }

    public int getA() {
        return a;
    }

    public void setA(int a) {
        this.a = a;
    }
}