【基础】Equal方法、面向对象-多态-继承-封装

package Test;

public class L3_1 {
    public static void main(String[] args)
    {
        C c1=new C(100);
        C c2=new C(100);
        System.out.println(c1.equals(c2));
    }
}
class B
{
    private int i;

    B(int i)
    {
        this.i=i;
    }
    public boolean equals(B b2)  //面向对象-->多态
    {
        if(this.i==b2.i)
            return true;
        else return false;
    }
}
class C extends B //面向对象-->继承
{
    private int j;
    C(int j)
    {
        super(j);    //初始化父类的带参数构造函数->B(int i)
        this.j=j;
    }
    public boolean equals(B b2)
    {
        C c=(C)b2;  //传递的参数是B类，需要强制转换
        if (this.j==c.j)
            return true;
        else return false;
    }
}