用了好長好長時間。。。。

從下午2:00上課到5:25下了課，吃過飯在宿舍還整了得有一個小時

加一塊兒將近五個小時，天啊！！！

原始碼：

import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.util.Random;
import java.util.Scanner;
public class SZYSfile {
 public static void main(String args[])throws IOException,ClassNotFoundException {
 
  File f = new File("C:\\Users\\劉世朝\\Desktop\\Test.txt");
  f.createNewFile();
  FileOutputStream fis = new FileOutputStream(f);
  OutputStreamWriter osw = new OutputStreamWriter(fis);
  int[] answer = new int [100];//存答案
  for(int i = 0 ; i < 100;i++) {
   int a = new Random().nextInt(10);//隨機數a
   int b = new Random().nextInt(10);//隨機數b
   int suijifu = new Random().nextInt(4);//隨機運算子
   String symbol=" ";
  switch(suijifu) {
      case(0):
           {symbol = "+";answer[i]=a+b;   break;}
      case(1):
           {symbol = "-";answer[i]=a-b;   break;}
      case(2):
           {symbol ="×";answer[i]=a*b;   break;}
      case(3):
                 if(b==0) { symbol = "+";answer[i]=a+b;   break;}
                  else
                   if(a%b!=0) {symbol = "-";answer[i]=a-b;   break;}
               else
                if(a%b==0) {symbol = "÷";answer[i]=a/b;   break;}
  } 
  osw.write(a+symbol+b+"=");
  osw.write("\r\n");
  }
  osw.close();
  //讀取檔案中的運算
  File file = new File("C:\\Users\\劉世朝\\Desktop\\Test.txt");
        int i=0;
       
        int score = 0;
        if(file.exists()){ 
            try { 
                FileReader fileReader = new FileReader(file); 
                BufferedReader br = new BufferedReader(fileReader); 
                String lineContent = null; 
                while((lineContent = br.readLine())!=null){ 
                    System.out.println(lineContent);
                  
                    Scanner input = new Scanner(System.in);
                    int a=input.nextInt();
                   
                    if(a==answer[i]) {
                     System.out.println("回答正確！");
                     score++;
                    }
                    else
                     {System.out.println("回答錯誤! 答案是"+answer[i]);}
                    
                    i++;
                } 
                br.close(); 
                fileReader.close(); 
               
            } catch (FileNotFoundException e1) { 
                System.out.println("no this file");//檔案不存在拋異常 
                e1.printStackTrace(); 
            } catch (IOException e1) { 
                System.out.println("io exception"); 
                e1.printStackTrace();
               
            }
        } System.out.println("分數為："+score);
  
    }
}

截圖：

問題：

首先是四則運算進一步完善了一下，隨機輸出字串，打亂+ - * ÷的順序。

然後是將四則運算題目輸出到txt文字檔案中，改過之後是用File的輸出。

最後是怎樣判斷答案對錯，運用兩個陣列對比，一個存答案，一個從資料臺輸入，然後再輸入到文字檔案中。