java习题1

题目:

建立一个学生类，有姓名，学号，3门课成绩，总分等信息，能输入输出学生数据，并能对总分进行排序，打印名次。

import java.lang.String;
import java.util.Scanner;
import java.util.Arrays;
import java.util.*;
//import java.lang.reflect;
class student implements Comparable
{
    Scanner a=new Scanner(System.in);
    String name;
    int number;
    double grade1,grade2,grade3;
    double sum;
    void get()
    {
        System.out.println("请输入学生姓名:");
        name=a.nextLine();
        System.out.println("请输入学生学号:");
        number=a.nextInt();
        System.out.println("请输入学生课程1成绩:");
        grade1=a.nextDouble();
        System.out.println("请输入学生课程2成绩:");
        grade2=a.nextDouble();
        System.out.println("请输入学生课程3成绩:");
        grade3=a.nextDouble();
        sum=grade1+grade2+grade3;
        System.out.println("学生信息录入成功!");        
    }
    void put()
    {
        System.out.println("学生姓名"+name+" "+"学生学号"+number);
        System.out.println("课程1"+" "+grade1);
        System.out.println("课程2"+" "+grade2);
        System.out.println("课程3"+" "+grade3);
        System.out.println("总分"+" "+sum);
        
    }
    public int compareTo(Object obj)
    {
        student p=(student)obj;
        if(p.sum>this.sum)
            return 1;
        else if(p.sum<this.sum)
        return -1;
        else {return 0;}
    }
    
}
public class aa 
{
    public static void main(String []args)
    {
        student a[]=new student[3];
        for(int i=0;i<3;i++)
        {
            a[i]=new student();
            a[i].get();
        }
        Arrays.sort(a);
        for(int i=0;i<3;i++)
            a[i].put();
     
    

    }
    
    
}