救命啊~~學長..:P
我的程式又有問題摟..:P
ㄚ我就一直想用java 的class來玩.
但是他就是不像c++一樣..
把class宣告成陣列純取成績..
怎麼搞都出問題><~~~
一直跑出java.lang.NullpointerException
import java.io.*;
import java.math.*;
/*
* 學生成幾處理系統1.2Beta版
* 本版本嘗試使用class和陣列來處理,
* 另外也加入搜尋的功能,儲存的功能.
*
*/
class StudentScore
{
int num;
int math;
int chinese;
int english;
String name;
public StudentScore(int m,int c,int e,String n )
{
name=n;
math=m;
english=e;
chinese=c;
}
public String GetName()
{
return name;
}
int total()
{
return math+chinese+english;
}//傳回總分
double avg()
{
return (math+chinese+english)/3;
}//傳回平均
public void Modify(int math,int english,int chinese)
{
this.math=math;
this.english=english;
this.chinese=chinese;
}
}//StudentScore
/**
* @com.register ( clsid=555D0FC4-C78F-11D4-83D1-0080C8D89738, typelib=555D0FC3-C78F-11D4-83D1-0080C8D89738 )
*/
public class score
{
public static void main(String args[])throws IOException{
BufferedReader br =new BufferedReader(new InputStreamReader(System.in));
int w=0,num=0;
String temp=null,temp1=null,temp2=null,temp3=null;
StudentScore S[] =new StudentScore[100];
System.out.println("\t歡迎進入學生成績處理系統1.2Beta版");
System.out.println("\t1)增加 ,2)修改 ,3)刪除 ,4)搜尋 ,5)列出 ,6)離開");
System.out.println("-----------------------------------------------------------------");
try{
System.out.flush();
temp=br.readLine();
w=Integer.parseInt(temp);
}
catch(ArithmeticException e)
{
System.out.println("It's a undefined number");
}
do{
switch(w){
case 1:
try{
++num;
System.out.print("請輸入姓名:");
System.out.flush();
temp=br.readLine();
System.out.print("請輸入國文成績:");
System.out.flush();
temp1=br.readLine();
c=Integer.parseInt(temp1);
System.out.print("請輸入英文成績:");
System.out.flush();
temp2=br.readLine();
e=Integer.parseInt(temp2);
System.out.print("請輸入數學成績:");
System.out.flush();
temp3=br.readLine();
m=Integer.parseInt(temp3);
StudentScore S[num]=new StudentScore(m,c,e,temp);
}
catch(IOException e)
{
System.out.println("It's a undefined number");
}
break;
case 2:
break;
case 3:
break;
case 4:
break;
case 5:
break;
case 6:
break;
default:
}//switch
}while(w==6);
}//main
}//score
--
※ 發信站: 批踢踢實業坊(ptt.twbbs.org)
◆ From: PCA70.PC.tmtc.edu.tw