20165303 2017-2018-2 《Java程序设计》结对编程练习_四则运算

• 需求分析
  能生成简单四则运算题目并判断用户回答对错。
  能正确统计回答正确的概率。
  能正确处理混合四则运算的优先级的问题。
  能正确输出负数等结果。
  能处理简单的加，减，乘，除运算。
  能正确的处理有括号的情况并输出正确的运算结果，能正确处理输入异常的情况。
• 运行截图
  

• 代码实现
  import java.util.;
  public class sizeyunsuan {
  public static void main(String[] args) {
  System.out.println("输入测试题数目：");
  Scanner sc=new Scanner(System.in);
  int number=sc.nextInt();
  double right = 0;
  double wrong = 0;
  for (int i = 0; i < number; i++) {
  System.out.println("第"+(i+1)+"道题,请在下方输入答案：");
  double op1=(int)(Math.random()10);
  double op2=(int)(Math.random()10);
  Random r3 = new Random();
  int m = r3.nextInt(4);
  char[] chs = {'+','-','','/'};
  String Operator = String.valueOf(chs[m]);
  //生成题目
  if(Operator.equals("+")){
  System.out.println(op1+"+"+op2+"=");
  boolean b = add(op1,op2);
  if(b == true){
  right++;System.out.println("right! ");
  }
  else{
  wrong++;System.out.println("no ");
  System.out.println("right answer: "+(op1+op2));
  }
  }
  else if(Operator.equals("-")){
  System.out.println(op1+"-"+op2+"=");
  boolean b =minus(op1,op2);
  if(b == true){
  right++;System.out.println("right! ");
  }
  else{
  wrong++;System.out.println("no ");
  System.out.println("right answer: "+(op1-op2));
  }
  }
  else if(Operator.equals("")){
  System.out.println(op1+"×"+op2+"=");
  boolean b =times(op1,op2);
  if(b == true){
  right++;System.out.println("right! ");
  }
  else{
  wrong++;System.out.println("no ");
  System.out.println("right answer: "+(op1op2));
  }
  }
  else{
  System.out.println(op1+"÷"+op2+"=");
  boolean b =Div(op1,op2);
  if(b == true){
  right++;System.out.println("right! ");
  }else{
  wrong++;System.out.println("no ");
  System.out.println("right answer: "+op1/op2);
  }
  }
  }
  System.out.println("做对了"+right+"道题.");
  System.out.println("做错了"+wrong+"道题.");
  System.out.println("正确率为"+(right/(wrong+right))100+"%");
  }
  private static boolean add(double x,double y) {
  Scanner sc = new Scanner(System.in);
  double num1 = sc.nextDouble();
  double result = x + y;
  if(num1 == result){
  return true;
  }else{
  return false;
  }
  }
  private static boolean minus(double x,double y) {
  Scanner sc = new Scanner(System.in);
  double num1 = sc.nextDouble();
  double result = x - y;
  if(num1 == result){
  return true;
  }else{
  return false;
  }
  }
  private static boolean times (double x,double y) {
  Scanner sc = new Scanner(System.in);
  double num1 = sc.nextDouble();
  double result = x y;
  if(num1 == result){
  return true;
  }else{
  return false;
  }
  }
  private static boolean Div(double x,double y) {
  Scanner sc = new Scanner(System.in);
  double num1 = sc.nextDouble();
  double result =x/y;
  if(num1 == result){
  return true;
  }else{
  return false;
  }
  }
  }

• whitestar运行图
  

• 码云链接
  https://gitee.com/BESTI-IS-JAVA-2018/20165303WeiYujava/tree/master/src

• 结对感受
  通过这周的不断修改代码，不断地和小伙伴争论，终于修改出了基本实现功能的代码，然后就是实现功能，但是在运行的过程中还是有一些bug，不是太完美，由于时间紧张，本周的实验比较多，然后实现的比较粗糙，我会在以后的学习过程中继续实现这个代码。