【第一周】四则运算

1.需求分析：对两个数字进行加减乘除四则运算

2.算法思想：

（1）随机获取两个数字和一个运算符构成一个表达式

（2）对表达式进行四则运算并输出对错

（3）统计输出答对和答错的次数

3.具体代码：

package ruan.jian.gong.cheng;

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

public class FigureOperate {
    public static void main(String[] args) {
        int rightNum = 0;//答对次数
        int wrongNum = 0;//答错次数
        for (int i =1; i <= 10; i++) {
            int num1 =(int) (Math.random() * 10);//随机获取第一个数字
            int num2 =(int) (Math.random() * 10);//随机获取第二个数字
            // 生成随机运算符
            Random num = new Random();
            int index = num.nextInt(3) + 1;
            char[] opes = { '+', '-', '*', '/' };
            String ope = String.valueOf(opes[index]);
            Scanner scan = new Scanner(System.in);
            if (opes.equals("+")) { // 进行加法运算
                System.out.print(num1 + "+" + num2 + "=");
                int input = scan.nextInt();
                int sum = num1 + num2;
                if (sum==input) {
                    System.out.println("正确");
                    rightNum++;
                } else {
                    System.out.println("错误");
                    wrongNum++;
                }
                System.out.println("正确答案是:" + sum);
            }else if (opes.equals("-")) { // 进行减法运算
                System.out.print(num1 + "-" + num2 + "=");
                int input = scan.nextInt();
                int sum = num1 - num2;
                if (sum==input) {
                    System.out.println("正确");
                    rightNum++;
                } else {
                    System.out.println("错误");
                    wrongNum++;
                }
                System.out.println("正确答案是:" + sum);
            }else if (opes.equals("*")) { // 进行乘法运算
                System.out.print(num1 + "*" +num2 + "=");
                int input = scan.nextInt();
                int sum = num1 * num2;
                if (sum==input) {
                    System.out.println("正确");
                    rightNum++;
                } else {
                    System.out.println("错误");
                    wrongNum++;
                }
                System.out.println("正确答案是:" + sum);
            }else {                     // 进行除法运算
                System.out.print(num1 + "/" + num2 + "=");
                int input = scan.nextInt();
                int sum = num1 / num2;
                if (sum==input) {
                    System.out.println("回答正确");
                    rightNum++;
                } else {
                    System.out.println("回答错误");
                    wrongNum++;
                }
            }
        }
        System.out.println("做对" + rightNum + "题");
        System.out.println("做错" + wrongNum + "题");
    }
}

4.输出结果