[数据结构与算法]javase 1-5 switch分支和Random类

1、switch

2、随机数Random类

案例：

随机数小游戏----猜数字

package com.itheima.random;

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

public class random_game {
    public static void main(String[] args) {
       Random random = new Random();
       int r = random.nextInt(100)+1; //生成1~100的随机数
        Scanner sc = new Scanner(System.in);
        System.out.println("请猜一个数字:");
        int guessNumber = sc.nextInt();
        while(r != guessNumber)
        {
            if(guessNumber>r)
            {
                System.out.println("太大了，小一点!");
                guessNumber = sc.nextInt();
                System.out.println("您输入的是:"+guessNumber);
            }
            else
            {
                System.out.println("太小了，大一点!");
                guessNumber = sc.nextInt();
                System.out.println("您输入的是:"+guessNumber);
            }
        }
        System.out.println("您猜对了");
        System.out.println("随机数是"+r);
    }
}