java基础之面向对象：继承，封装，多态

父类：学生
私有属性：名字 学号
方法：构造函数，
set/get test(int score) 判断是否及格

子类 大学生 （extends）
私有属性：主修专业/学分
方法：构造

public class Student {
    private String s_name;
    private String s_num;

    public String getS_num() {
        return s_num;
    }

    public void setS_num(String s_num) {
        this.s_num = s_num;
    }

    public String getS_name() {
        return s_name;
    }

    public void setS_name(String s_name) {
        this.s_name = s_name;
    }


    public Student(){};
    public Student( String s_name,String s_num){
        this.s_name=s_name;
        this.s_num=s_num;
    }

 public void test(int score){
        if((score<0)|(score>100)){
            System.out.println("成绩无效");
        }else{
            if(score>60){
                System.out.println("考试合格");
            }

     }
 }


}

public class CollegeStudent extends Student{
    private String major;
    private int credit;

    public String getMajor() {
        return major;
    }

    public void setMajor(String major) {
        this.major = major;
    }

    public int getCredit() {
        return credit;
    }

    public void setCredit(int credit) {
        this.credit = credit;
    }


    public CollegeStudent(){
        super();}

    public CollegeStudent(String s_name,String s_num,String major,int credit){
        super(s_name,s_num);
        this.major=major;
        this.credit=credit;
    }


    public void test(int score,int credit){
        if(score<0||score>100){
            System.out.println("成绩无效");
        }else{
            if(score>60){

                System.out.println("考试合格，学分增加："+credit+"分");
                System.out.println();
                this.credit+=credit;
                System.out.println("现有学分："+this.credit+"分");
            }else{
                System.out.println("考试不及格");
            }

        }
    }

}