import java.util.Random;

public class randomDemo {
    public static void main(String[] args) {
           randomTest();
    }
    public static void randomTest(){
        //Random产生随机数
        Random r=new Random();
        for (int i=1;i<10;i++){
            int num= r.nextInt(50)+1;
            System.out.println(num);
        }
        System.out.println("---------");
        //产生20到80之间的随机数
       for (int i=1;i<=10;i++){
           int num=r.nextInt(61)+20;
           System.out.println(num);
       }

    }
}