Java实验项目二——小学生考试系统(简单四则运算)

Program：设计实现一个小学生数学考试系统，完成随机出题（简单的四则运算），学生答题，自动判分的功能。

Description：代码如下：

/*
 * Description:面向考试系统建立类TestSystem
 * 
 * */

package entity;

public class TestSystem {

    private int num1;            //声明两个操作数
    private int num2;
    private String operateEle;        //声明操作符
    private static int grade = 0;        //记录最后得分
    
    //定义无参构造方法
    public TestSystem() {
        
    }
    
    //定义带参数的构造方法
    public TestSystem(int num1,int num2,String operateEle) {
        
        this.num1 = num1;
        this.num2 = num2;
        this.operateEle = operateEle;
    }

    //设置setter()和getter()方法
    public int getNum1() {
        return num1;
    }

    public void setNum1(int num1) {
        this.num1 = num1;
    }

    public int getNum2() {
        return num2;
    }

    public void setNum2(int num2) {
        this.num2 = num2;
    }
    
    //覆写toString()方法
    public String toString() {
        
        return this.num1 + this.operateEle + this.num2;
    }
    
    //取得表达式的正确结果
    public int getResult() {
        
        int result = 0;
        switch(this.operateEle) {
        
            case "+": result = this.num1 + this.num2;break;
            
            case "-": result =  this.num1 - this.num2;break;
            
            case "*": result =  this.num1 * this.num2;break;
            
            case "/": result =  this.num1 / this.num2;break;
        }
        
        return result;
    }
    
    //向屏幕输出总成绩
    public static void getGrade() {
        
        System.out.println( "考试结束，最后成绩为：" + TestSystem.grade );
    }
    
    //答对问题，将对应的成绩加入总成绩
    public static void setGrade(int grade) {
        
        TestSystem.grade += grade;
    }
    
    //将总成绩清零
    public static void clear() {

        TestSystem.grade = 0;
    }
    
    
}

/*
 * Description:定义类Operate,用于获取随机操作数和操作符
 * 
 * */


package tools;

import java.util.Random;
import java.util.Scanner;

public class Operate {
    
    //定义方法，返回一个100以内的随机数
    public static int getRandom() {
        
        Random ran = new Random();
        
        return ran.nextInt(100);  
    }
    
    //定义方法，返回操作符
    public static String getOperateEle() {
        
        String[] operateEle = {"+","-","*","/"};
        Random ran = new Random();
        
        return operateEle[ran.nextInt(4)];
    }
    
    
    //定义方法，取得用户输入的结果
    public static int getInput() {
        
        Scanner scan = new Scanner(System.in);        //实例化Scanner对象
        int result = 0;
        
        System.out.println( "请输入结果：" );
        result = scan.nextInt();
        return result;
        
    }
    
    
}

/*
 * Description:小学简单四则运算，系统随即出题，每题20分
 * 
 * Written By:Cai
 * 
 * Date Written:2017-09-25
 * 
 * */

package main;

import tools.Operate;        //导入自定义的两个类
import entity.TestSystem;

public class DemoTwo4 {

    public static void main(String args[]) {
        
        int i = 0;        //记录答题个数
        int inputResult = 0;        //接收用户输入的结果
        do {
            //实例化TestSystem类型对象
            TestSystem ts = new TestSystem(Operate.getRandom(),Operate.getRandom(),Operate.getOperateEle());
            System.out.println(ts);                    //输出表达式
            inputResult = Operate.getInput();        //用户输入
            if( inputResult == ts.getResult() ) {    //回答正确，加上对应的分值分
                
                System.out.println( "回答正确!" );    
                TestSystem.setGrade(20);            
            }else {                                    //回答错误
                
                System.out.println( "回答错误！" );
            }
            i++;
            
        }while(i < 5);                                //一共五道题（方便验证）
        
        TestSystem.getGrade();                        //打印最后结果
        TestSystem.clear();                        //总成绩清零                    
        
    }
}