java中list集合求学生总成绩,求张三和李四的总成绩,用循环判断的形式实现

Posted 2023-04-12

public class Stu
public String name;
public String course;
public int score;
public int total;

public Stu(String name,String course,int score)
this.name=name;
this.course=course;
this.score=score;

public String getName()
return name;

public int getScore()
return score;

public int getTotal()
return total;

public void setTotal(int total)
this.total=total;

public static void main(String[] args)
List<Stu> list=new ArrayList<Stu>();
Stu stu0=new Stu("张三","语文",60);
Stu stu1=new Stu("张三","数学",70);
Stu stu3=new Stu("李四","语文",65);
Stu stu4=new Stu("李四","数学",75);
list.add(stu0);
list.add(stu1);
list.add(stu3);
list.add(stu4);

package image;

import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.List;

public class Stu 
    public String name;
    public String course;
    public int score;
    public int total;

    public Stu(String name, String course, int score) 
        this.name = name;
        this.course = course;
        this.score = score;
    

    public String getName() 
        return name;
    

    public int getScore() 
        return score;
    

    public int getTotal() 
        return total;
    

    public void setTotal(int total) 
        this.total = total;
    

    public static void main(String[] args) 
        List<Stu> list = new ArrayList<Stu>();
        Stu stu0 = new Stu("张三", "语文", 60);
        Stu stu1 = new Stu("张三", "数学", 70);
        Stu stu3 = new Stu("李四", "语文", 65);
        Stu stu4 = new Stu("李四", "数学", 75);
        list.add(stu0);
        list.add(stu1);
        list.add(stu3);
        list.add(stu4);
        // 总成绩
        BigDecimal totalB = new BigDecimal("0");
        BigDecimal totalZhangsan = new BigDecimal("0");
        BigDecimal totalLisi = new BigDecimal("0");
        for (Stu stu : list) 
            totalB = totalB.add(new BigDecimal(stu.getScore() + ""));
            if ("张三".equals(stu.getName())) 
                totalZhangsan = totalZhangsan.add(new BigDecimal(stu.getScore() + ""));
            else if ("李四".equals(stu.getName())) 
                totalLisi = totalLisi.add(new BigDecimal(stu.getScore() + ""));
            
        
        System.out.println(totalB.doubleValue());
        System.out.println(totalZhangsan.doubleValue());
        System.out.println(totalLisi.doubleValue());

    

使用BigDecimal避免分数为小数时失真
结果为:
总成绩:270.0    
张三：130.0    
李四:140.0    

参考技术A public static void main(String[] args)

List<Stu> list = new ArrayList<Stu>();
Stu stu0=new Stu("张三","语文",60);
Stu stu1=new Stu("张三","数学",70);
Stu stu3=new Stu("李四","语文",65);
Stu stu4=new Stu("李四","数学",75);
list.add(stu0);
list.add(stu1);
list.add(stu3);
list.add(stu4);

int sumScore = 0;//声明变量保存学生总成绩
int zhangsanSumScore = 0;//声明变量保存张三总成绩
int lisiSumScore = 0;//声明变量保存李四总成绩

for (Stu stu : list) //循环list

sumScore = sumScore + stu.getScore();//计算总成绩

if( stu.getName().equals("张三") )//如果姓名是张三，则计算成绩

zhangsanSumScore = zhangsanSumScore + stu.getScore();

else//否则就是李四的成绩
lisiSumScore = lisiSumScore + stu.getScore();



System.out.println("学生总成绩为"+sumScore);
System.out.println("张三总成绩为"+zhangsanSumScore);
System.out.println("李四总成绩为"+lisiSumScore);
参考技术B //使用map存储总成绩，key：学生姓名  value：学生成绩
Map<String,Integer> map = new HashMap<String,Integer>();
for(Stu stu:list) 
 if(!map.containsKey(stu.getName))
 map.put(stu.getName,stu.getScore());
 else
 map.put(stu.getName,map.get(stu.getName)+stu.getScore());
 

System.out.println(map);

asp:查询每个学生的各科成绩，总分，平均分的sql语句

只有一个score表，字段是：xjh name zuohao xueke score
L001 张三 01 语文 65
L002 李四 02 数学 85
L001 张三 01 数学 75
L002 李四 02 语文 55

我想要的结果是： xjh name zuohao yuwen shuxue zongfen pjf
L001 张三 01 65 75 140 70
L002 李四 02 55 85 140 70

下面是我的sql语句：
dim rs,sql,sql2,zt,ck,nf,xq,cx,bj,bjmc,info

nf="2016"
xq="春季学期"
cx="期中考试"
bjmc="小学2012级3班"
set rs=server.CreateObject("Adodb.Recordset")
sql="select zuohao,name,xjh,"
sql=sql&"sum(case when xueke='语文' then score else 0 end) as yuwen,"
sql=sql&"sum(case when xueke='数学' then score else 0 end) as shuxue,"
sql=sql&"sum(case when xueke='英语' then score else 0 end) as yingyu,"
sql=sql&"sum(case when xueke='综合' then score else 0 end) as zhonghe,"
sql=sql&"sum(score) as zongfen,"
sql=sql&"sum(score)*1.0/4 as pjf"
sql=sql&" from score where nianfen='"&nf&"' and xueqi='"&xq&"' and cixu='"&cx&"' and bjmc='"&bjmc&"' group by zuohao,name,xjh order by desc zongfen"
rs.open sql,conn,1,1

提示错误：错误 '80004005' ，/StudentScore.asp，行 92 （注：92行就是：rs.open sql,conn,1,1）

怎么办啊？谢谢大虾

参考技术A dim rs,sql,sql2,zt,ck,nf,xq,cx,bj,bjmc,info

nf="2016"
xq="春季学期"
cx="期中考试"
bjmc="小学2012级3班"
set rs=server.CreateObject("Adodb.Recordset")
sql="select zuohao,name,xjh,"
sql=sql&"sum(case when xueke='语文' then score else 0 end) as yuwen,"
sql=sql&"sum(case when xueke='数学' then score else 0 end) as shuxue,"
sql=sql&"sum(case when xueke='英语' then score else 0 end) as yingyu,"
sql=sql&"sum(case when xueke='综合' then score else 0 end) as zhonghe,"
sql=sql&"sum(score) as zongfen,"
sql=sql&"sum(score)*1.0/4 as pjf"
sql=sql&" from score where nianfen='"&nf&"' and xueqi='"&xq&"' and cixu='"&cx&"' and bjmc='"&bjmc&"' group by zuohao,name,xjh order by zongfen desc "
rs.open sql,conn,1,1追问

错在哪个地方哦？没看出来，先谢过了

追答

order by desc zongfen 写错了
-->order by zongfen desc

追问

我改过来了，还是提示同样的错误代码