Java：面积，圆周率，重载，对象数组，商品管理系统，登录，查询所有和单个，修改商品
//一、在Shape类中添加计算面积的重载并调用。
//重载1：double（正方形面积）
//重载2：double,double（长方形面积）
//重载3：int,double(圆形面积)
package a;
public class Shape {
public static void main(String[] args) {
Shape changfangxing = new Shape();
changfangxing.chang = 1;
changfangxing.kuan = 3;
Shape zhengfangxing = new Shape();
zhengfangxing.lengchang = 2;
Shape yuanxing = new Shape();
yuanxing.banjing = 3;
// jx.setKuan(11);
//
// jx.setChang(2);
int changfangxingzhouchang = changfangxing.changfangxingzhouchang();
int changfangxingmianji = changfangxing.changfangxingmianji();
double yuanxingmianji = yuanxing.yuanxingmianji();
double yuanxingzhouchang = yuanxing.yuanxingzhouchang();
int zhengfangxingmianji = zhengfangxing.zhengfangxingmianji();
int zhengfangxingzhouchang = zhengfangxing.zhenfangxingzhouchang();
System.out.println("长方形周长为" + changfangxingzhouchang + ",长方形面积"
+ changfangxingmianji);
System.out.println("正方形周长为" + zhengfangxingzhouchang + ",正方形面积"
+ zhengfangxingmianji);
System.out.println("圆形周长为" + yuanxingzhouchang + ",圆形面积"
+ yuanxingmianji);
}
private int banjing;
private int chang;
private int kuan;
private int lengchang;
public int changfangxingmianji() {
return (this.kuan * this.chang);
}
public int changfangxingzhouchang() {
return ((this.kuan + this.chang) * 2);
}
public int getBanjing() {
return banjing;
}
public int getChang() {
return chang;
}
public int getKuan() {
return kuan;
}
public int getLegnchang() {
return lengchang;
}
public void setbanjing(int banjing) {
this.banjing = banjing;
}
public void setBanjing(int banjing) {
this.banjing = banjing;
}
public void setChang(int chang) {
this.chang = chang;
}
public void setKuan(int kuan) {
this.kuan = kuan;
}
public void setLegnchang(int legnchang) {
this.lengchang = legnchang;
}
public void setlengchang(int lengchang) {
this.lengchang = lengchang;
}
public double yuanxingmianji() {
return (this.banjing * this.banjing * (Math.PI));
}
public double yuanxingzhouchang() {
return (this.banjing * 2 * (Math.PI));
}
public int zhenfangxingzhouchang() {
return (this.lengchang * 4);
}
public int zhengfangxingmianji() {
return (this.lengchang * this.lengchang);
}
}
//二、使用对象数组制作商品管理系统：
//1.用户登录
//2.查询所有商品
//3.查询单个商品
//4.修改商品信息
//思路:
// 1.商品管理系统是不是首先要有商品，是不是，所以 我们要先声明商品类（商品编号，名称，价格）。方法:介绍 商品，我们就使用toString()进行介绍,记得在构造方法中对 属性进行赋值，并设置get/set方法,商品类完毕
// 2.用户登录，所以我们还要有个用户类，用户包含用 户名和密码两个属性，因为只要比较用户输入的用户名和秘密 是否一致只是获取，所以只设置其get方法即可,用户类完毕
// 3.制作登录功能,登录的时候提示用户输入用户名和 密码，输入错误提示用户名或密码错误，正确就到商品的主界 面
// 4.查询所有商品的功能,既然要查询商品，查询那些 商品呢?是不是要有一个容器来存储商品，所以我们定义一个 对象数组来存储商品
// 5.查询所有商品，其实就是将商品的容器里的内容进 行遍历出来,那么我们写一个for循环将其内容遍历一下就可以 啦
// 6.根据编号查询单个商品，首先要提示用户输入一个商品编号，进行比较一下对象数组中有没有这个编号，有就打印其信息，没有就打印商品不存在
// boolean b=true;//b默认使true，如果查到这个商品b就使false,如果商品遍历完毕b还是true，说明该商品不存在
// 7.修改商品的操作,首先要提示用户要修改那个商品，所以第一步要提示用户输入一个商品编号，接收到编号后还是要比较一下这个商品存不存在，如何比较，参照步骤6，
//接收完毕后将接收到的内容赋值给该商品就完成啦！
package a;
import java.util.Scanner;
public class fuxi {
public static void main(String[] args) {
shangpin[] sp = { new shangpin("1", "诗书画唱限量周边", 99),
new shangpin("2", "诗书画唱牌限量机器人", 9999),
new shangpin("3", "诗书画唱教程", 999),
new shangpin("4", "诗书画唱限量CD", 999),
new shangpin("5", "《诗书画唱自传》", 99) };
Scanner s = new Scanner(System.in);
yonghu y = new yonghu();
while (true) {
System.out.println("欢迎来到诗书画唱商品管理系统");
System.out.println("请登录！先点赞!先投币！先收藏！先三连!先关注！");
System.out.println("请输入用户名:");
String uname = s.next();
System.out.println("请输入密码:");
String pwd = s.next();
if (y.getUname().equals(uname) && y.getPwd().equals(pwd)) {
break;
} else {
System.out.println("用户名或密码输入错误,请重新输入！点个赞！点个关注！");
}
}
System.out.println("登录成功!");
while (true) {
System.out.println("请输入你要执行的操作:1.查询所有商品2. 根据编号查询单个商品3.修改商品信息 ");
int nums = s.nextInt();
if (nums == 1) {
for (int i = 0; i < sp.length; i++) {
System.out.println(sp[i].toString());
}
} else if (nums == 2) {
System.out.println("请输入你要查询的商品编号");
String snum = s.next();
boolean b = true;
for (int i = 0; i < sp.length; i++) {
if (sp[i].getBianhao().equals(snum)) {
System.out.println(sp[i].toString());
b = false;
}
}
if (b) {
System.out.println("商品不存在，三连啊！");
}
}
else if (nums == 3) {
System.out.println("请输入你要修改的商品编号");
String bianhao = s.next();
boolean b = true;
for (int i = 0; i < sp.length; i++) {
if (sp[i].getBianhao().equals(bianhao)) {
System.out.println("请输入该商品的新名称");
String newname = s.next();
System.out.println("请输入该商品的新价格，点赞！");
double newprice = s.nextDouble();
sp[i].setName(newname);
sp[i].setPrice(newprice);
b = false;
}
}
if (b) {
System.out.println("商品不存在，点赞！");
}
} else {
System.out.println("输入错误，投币！");
}
}
}
}
class shangpin {
private String bianhao;
private String name;
private double price;
public shangpin(String bianhao, String name, double price) {
this.bianhao = bianhao;
this.name = name;
this.price = price;
}
public String getBianhao() {
return bianhao;
}
public String getName() {
return name;
}
public double getPrice() {
return price;
}
public void setBianhao(String bianhao) {
this.bianhao = bianhao;
}
public void setName(String name) {
this.name = name;
}
public void setPrice(double price) {
this.price = price;
}
@Override
public String toString() {
return "商品编号：" + bianhao + ",商品名称：" + name + ",商品价格：" + price;
}
}
class yonghu {
private String pwd = "222";
private String uname = "111";
public String getPwd() {
return pwd;
}
public String getUname() {
return uname;
}
public void setPwd(String pwd) {
this.pwd = pwd;
}
public void setUname(String uname) {
this.uname = uname;
}
}
