[笔记]类与集合练习之点名器+库存清单-06day

q59541511

学生类

[Java] 纯文本查看 复制代码

public class Student{
	String name;
	int ages;
}

[Java] 纯文本查看 复制代码

import java.util.ArrayList; //集合类
import java.util.Random;  //生成随机数类
public class CallNames{
        public static void main(String[] args){
                ArrayList<Student> array = new ArrayList<Student>();
                addnames(array);
                printnames(array);
                PointsNames(array);
                
        }
        //创建学生数据录入集合的方法 传入集合类型 无返回值
        public static void addnames(ArrayList<Student> arr){
                //内存中创建6个学生
                Student s1 = new Student();
                Student s2 = new Student();
                Student s3 = new Student();
                Student s4 = new Student();
                Student s5 = new Student();
                Student s6 = new Student();
                //对学生进行赋值初始化
                s1.name = "张三";
                s1.ages = 15;
                s2.name = "小花";
                s2.ages = 17;
                s3.name = "王二麻";
                s3.ages = 18;
                s4.name = "哈哈";
                s4.ages = 21;
                s5.name = "小狗";
                s5.ages = 31;
                s6.name = "瞎猫";
                s6.ages = 41;
                //将学生放进集合内
                arr.add(s1);
                arr.add(s2);
                arr.add(s3);
                arr.add(s4);
                arr.add(s5);
                arr.add(s6);
        }
        //从集合中遍历学生显示所有学生 传入集合类型 无返回值
        public static void printnames(ArrayList<Student> arr){
                for(int i = 0;i < arr.size();i++){
                        //将集合中的学生转化为学生类型,从而显示学生信息
                        Student s = arr.get(i);
                        System.out.println(s.name+"    "+s.ages);
                }
        }
        //生成随机数进行学生点名 传入集合类型 有返回值String
        public static void PointsNames(ArrayList<Student> arr){
                Random r = new Random();
                Student s = arr.get(r.nextInt(arr.size()));
                System.out.println("点名如下\r 姓名:"+s.name+"    年龄:"+s.ages);
        }
        
}

q59541511

这个是昨天库存升级版运用的ArrayList类
Goods类

[Java] 纯文本查看 复制代码

public class Goods{
	String name ;
	double price ;
	int count ;
}

main类

[Java] 纯文本查看 复制代码

import java.util.ArrayList;
import java.util.Scanner;
public class Shop{
        public static void main(String[] args){
                ArrayList<Goods> array = new ArrayList<Goods>();
                addGoods(array);
                while(true){
            switch(choose()){
                case 1:
                printgoods(array);
                break;
                 
                case 2:
                changeconut(array);
                break;
                 
                case 3:
                return;
                 
                default:
                System.out.println("您输入的数字不正确哦");
            }
        }
        }
        //选择方法
         public static int choose(){
        System.out.println("1.查看所有库存清单");
        System.out.println("2.修改库存清单");
        System.out.println("3.退出");
        System.out.println("请输入相对应的数字进行选择");
        Scanner sc = new Scanner(System.in);
        int number = sc.nextInt();
        return number;
    }
        //创建商品方法
        public static void addGoods(ArrayList<Goods> arr){
                //实例化商品
                Goods G1 = new Goods();
                Goods G2 = new Goods();
                Goods G3 = new Goods();
                Goods G4 = new Goods();
                //对商品进行赋值
                G1.name = "芬达";
                G1.price = 3.3;
                G1.count = 0;
                G2.name = "可乐";
                G2.price = 3.5;
                G2.count = 0;
                G3.name = "脉动";
                G3.price = 4;
                G3.count = 0;
                G4.name = "中沃";
                G4.price = 5;
                G4.count = 0;
                //将商品录入数组中
                arr.add(G1);
                arr.add(G2);
                arr.add(G3);
                arr.add(G4);
        }
        //循环遍历集合 并算出总价总数
        public static void printgoods(ArrayList<Goods> arr){
                System.out.println("---------商品如下--------");
                System.out.println("商品名称    "+"商品价格     "+"商品库存");
                double sumprice = 0;
                int sumgoods = 0;
                for(int i = 0;i < arr.size();i++){
                        Goods g = arr.get(i);
                        System.out.println(g.name+"     "+g.price+"     "+g.count);
                        sumprice += g.price * g.count;
                        sumgoods += g.count;
                }
                System.out.println("-----------------------\n商品总价为:"+sumprice+"\n商品总数量为"+sumgoods);
        }
        //修改库存方法
        public static void changeconut(ArrayList<Goods> arr){
                Scanner sc = new Scanner(System.in);
                for(int i = 0 ;i < arr.size();i++){
                        Goods G = arr.get(i);
                        System.out.println("请您修改商品"+G.name+"的数量");
                        G.count = sc.nextInt();
                }
        }
}

小生爱吃醋

用array的自带方法啊

dpqlovehack

貌似很高深的样子！

wmzh0521

刚学到数组。三天，刚到数组，学的有点细了，每个东西都在琢磨好半天，然后再去啃经典例题，速度甚是不能看。