Java基础-day04-代码题

package StudyJavaSEday04;
import java.util.Random;
import java.util.Scanner;
/**
 * 1.键盘录入班级人数
 * 2.根据录入的班级人数创建数组
 * 3.利用随机数产生0-100的成绩(包含0和100)
 * 4.要求:
 *  (1)打印该班级的不及格人数
 *  (2)打印该班级的平均分
 *  (3)演示格式如下:
 *  请输入班级人数:
 *  键盘录入:100
 *  控制台输出:
 *  不及格人数:19
 *  班级平均分:87
 * @author 奋斗蒙
 *
 */
public class ShuZudaima01 {
 public static void main(String[] args) {
 Scanner sc = new Scanner(System.in);
 System.out.println("请输入班级人数：");
 int  Renshu = sc.nextInt();
 int [] Student = new int [Renshu];
 //不及格人数统计初始化
 int count = 0;
 //学生总分初始化
 int source = 0;
 Random random = new Random();
 for (int i = 0; i < Student.length; i++) {
 Student[i] = random.nextInt(101);
 System.out.println(Student[i]);
 if (Student[i]<60) {
 count++;
 }
 source+=Student[i];
 }
 System.out.println("不及格人数："+count);
 System.out.println("班级平均分："+source/Student.length);
 }
}

package StudyJavaSEday04;
import java.util.Random;
import java.util.Scanner;
public class Demo {
 public static void main(String[] args) {
 Scanner sc = new Scanner(System.in);
 System.out.println("请输入班级总组数：");
 int a = sc.nextInt();
 System.out.println("请输入班级中每组的人数：");
 int b = sc.nextInt();
 int[][] arr = new int[a][b];
 Random r = new Random();
 int avg = 0;
 for (int i = 0; i < arr.length; i++) {
 int count = 0;
 int source = 0;
 for (int j = 0; j < arr[i].length; j++) {
 arr[i][j] = r.nextInt(101);
 if (arr[i][j] < 60) {
 count++;
 }
 source += arr[i][j];
 }
 int avg1 = source / arr[i].length;
 System.out.println("第" + (i + 1) + "组不及格人数为：" + count + "人");
 System.out.println("第" + (i + 1) + "组平均分为：" + avg1);
 if (avg1 > avg) {
 avg = avg1;
 }
 }
 System.out.println("班级中单组最高平均分为：" + avg);
 }
}

package StudyJavaSEday04;
/**
 * 分析:
 * 要做的随机点名器，它具备以下3个内容：
 *  存储所有武将姓名 --> String[]
 *  总览武将 --> 遍历数组
 *  随机点名其中一人，打印到控制台 --> Random类
 *  @author 奋斗蒙
 */
import java.util.Random;
public class RandomName {
 public static void main(String[] args) {
 // 存储所有武将姓名 --> String[]
 String[] names = { "赵云", "张飞", "关羽", "黄忠", "马超","魏延","廖化","张苞","关平","关兴","姜维",};
 // 总览武将 --> 遍历数组
 System.out.println("=============所有武将==================");
 for (int i = 0; i < names.length; i++) {
 System.out.println("第" + (i + 1) + "武将的姓名是: " + names[i]);
 }
 // 随机点名其中一人，打印到控制台 --> Random类
 Random r = new Random();
 // System.out.println(r);//java.util.Random@1e58cb8
 // 在数组的范围内随机产生一个数
 int number = r.nextInt(names.length);// names.length = 5
 // 通过产生的随机数,在数组中查找对应的元素(索引)
 String name = names[number];// number 0,1,2,3,4
 System.out.println("============================================");
 System.out.println("要出战的武将是: " + name);
 }
}