Java对象数组练习

• 定义数组存储三个商品对象，商品的属性：id，名字，价格，库存，创建三个商品对象，并把商品对象存入到数组中

public class Goods {
    private String id;
    private String name;
    private double price;
    private int count;
 
    public Goods(){
 
    }
 
    public Goods(String id, String name, double price, int count) {
        this.id = id;
        this.name = name;
        this.price = price;
        this.count = count;
    }
 
    public String getId() {
        return id;
    }
 
    public void setId(String id) {
        this.id = id;
    }
 
    public String getName() {
        return name;
    }
 
    public void setName(String name) {
        this.name = name;
    }
 
    public double getPrice() {
        return price;
    }
 
    public void setPrice(double price) {
        this.price = price;
    }
 
    public int getCount() {
        return count;
    }
 
    public void setCount(int count) {
        this.count = count;
    }
}

public class GoodsTest {
    public static void main(String[] args) {
        //创建一个数组,动态初始化
        Goods[] arr = new Goods[3];
 
        //创建三个商品对象
        Goods g1 = new Goods("001","华为mate60",5999.0,100);
        Goods g2 = new Goods("002","保温杯",227.0,200);
        Goods g3 = new Goods("003","宁夏枸杞",12.7,70);
 
        //把商品添加到数组
        arr[0] = g1;
        arr[1] = g2;
        arr[2] = g3;
 
        for (int i = 0; i < arr.length; i++) {
            Goods goods = arr[i];
            System.out.println(goods.getId() + ", " + goods.getName() + ", " + goods.getPrice() + ", " + goods.getCount());
        }
    }
}

定义数组存储3部汽车对象，汽车的属性：品牌，价格，颜色。创建三个汽车对象，数据通过键盘录入而来，并把数据存入到数组中。

• 键盘录入
  • Java里面有一个类叫Scanner，可以接收键盘输入的数字
  • 第一步：导包，找Scanner这个类
    • import java.util.Scanner;
    • 导包必须在类定义的上边（public class上面）
  • 第二步：创建对象，开始使用Scanner这个类
    • Scanner sc = new Scanner(System.in);
    • sc为变量名可以改变，其他不能改
  • 第三步：接收数据
    • int i = sc.nextInt();
    • i为变量名可以改变，其他不能改
  • 注意：这种方式只能接收整数，输入字符小数会报错
  • 第一套体系(遇到空格、制表符、回车就停止接收，后面的数据不接收)
    • nextInt(); 接收整数
    • nextDouble(); 接收小数
    • next(); 接收字符串

    • 

    • 

  • 第二套体系(可以接收空格、制表符，遇到回车才停止接收)
    • nextLine(); 接收字符串
  • 两套体系不能混用，容易出错

public class Car {
    private String brand;
    private int price;
    private String color;
 
    public Car() {
 
    }
 
    public Car(String brand, int price, String color) {
        this.brand = brand;
        this.price = price;
        this.color = color;
    }
 
    public String getBrand() {
        return brand;
    }
 
    public void setBrand(String brand) {
        this.brand = brand;
    }
 
    public int getPrice() {
        return price;
    }
 
    public void setPrice(int price) {
        this.price = price;
    }
 
    public String getColor() {
        return color;
    }
 
    public void setColor(String color) {
        this.color = color;
    }
}

import java.util.Scanner;
 
public class CarText {
    public static void main(String[] args) {
        //创建一个数组存储汽车对象
        Car[] arr = new Car[3];
 
        //创建汽车对象，数据来自键盘录入
        Scanner sc = new Scanner(System.in);
        for (int i = 0; i < arr.length; i++) {
            //创建汽车的对象
            Car c = new Car();
            //录入品牌
            System.out.println("请输入汽车的品牌");
            String brand = sc.next();
            c.setBrand(brand);
            //录入价格
            System.out.println("请输入汽车的价格");
            int price = sc.nextInt();
            c.setPrice(price);
            System.out.println("请输入汽车的颜色");
            String color = sc.next();
            c.setColor(color);
 
            //把汽车对象添加到数组中
            arr[i] = c;
        }
 
        //遍历数组
        for (int i = 0; i < arr.length; i++) {
            Car car = arr[i];
            System.out.println(car.getBrand() + ", " + car.getPrice() + ", " + car.getColor());
        }
 
 
    }
}