P335_0334韩顺平Java_零钱通介绍

1. 先完成显示菜单，并可以选择。
2. 完成零钱通明细。
3. 完成收益入账。
4. 消费。
5. 退出。

PS：判断时尽量用不正确的条件去过滤，用正确条件过滤太繁琐

代码

过程编程

package smallchange;import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Scanner;public class SmallChange {public static void main(String[] args) {boolean loop = true;Scanner scanner = new Scanner(System.in);String key = ""; // enter stringString details = "----------- Details -----------";String exit = new String();double money = 0;double balance = 0;Date date = null;SimpleDateFormat sdf = new SimpleDateFormat("yyy-MM-dd HH:mm");String note = "";do {System.out.println("\n\n\n=========== Menu ===========");System.out.println("\t\t# 1 Details.");System.out.println("\t\t# 2 Income.");System.out.println("\t\t# 3 Consume.");System.out.println("\t\t# 4 Exit.");System.out.print("# Please enter your selection(1~4):");key = scanner.next();switch (key) {case "1":System.out.println(details);break;case "2":while (true) {System.out.print("# The account of income is:");money = scanner.nextDouble();if (money <= 0) {System.out.println("# Error, The account of income need greater than 0!");} else {break;}}balance += money;date = new Date();details += "\nIncome: +" + money + "\tTime:" + sdf.format(date) + "\tBalance:" + balance;break;case "3":while (true) {System.out.print("# The account of consume is:");money = scanner.nextDouble();if (money <= 0 || money > balance) {System.out.println("# Error, The account of consume need greater than 0 and less than " + balance);} else {break;}}balance -= money;System.out.print("# The description of consume is:");note = scanner.next();details += "\nConsume: -" + money + "\tTime:" + sdf.format(date) + "\tBalance:" + balance + "\tNote:" + note;break;case "4":
//                    enter inwhile (true) {System.out.println("# Are sure you want exit?(y\\n)");exit = scanner.next();if (exit.equals("y") || exit.equals("n")) {break;} else {System.out.println("# Error, please enter again!");}}
//                    exit or notif (exit.equals("y")) {loop = false;System.out.println("=========== Exit ===========");} else if (exit.equals("n")) {continue;}break;default:System.out.println("# Error, please enter your selection again!");}} while (loop);}}

OOP（Object-Oriented Project）

package smallchange;import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Scanner;public class SmallChangeOOP {private boolean loop = true;private final Scanner scanner = new Scanner(System.in);private String key = ""; // enter string to select function.private String details = "----------- Details -----------";private String exit = "";// enter y\n to exitprivate double money = 0;private double balance = 0;private Date date = null;private SimpleDateFormat sdf = new SimpleDateFormat("yyy-MM-dd HH:mm");private String note = "";public void mainMenu() {do {System.out.println("\n=========== Menu ===========");System.out.println("\t\t# 1 Details.");System.out.println("\t\t# 2 Income.");System.out.println("\t\t# 3 Consume.");System.out.println("\t\t# 4 Exit.");System.out.print("# Please enter your selection(1~4):");key = scanner.next();switch (key) {case "1":this.details();break;case "2":this.income();break;case "3":this.consume();break;case "4":this.exit();break;default:System.out.println("# Error, please enter your selection again!");}} while (loop);}public void details() {System.out.println(details);}public void income() {while (true) {System.out.print("# The account of income is:");money = scanner.nextDouble();if (money <= 0) {System.out.println("# Error, The account of income need greater than 0!");} else {break;}}balance += money;date = new Date();details += "\nIncome: +" + money + "\tTime:" + sdf.format(date) + "\tBalance:" + balance;}public void consume() {while (true) {System.out.print("# The account of consume is:");money = scanner.nextDouble();if (money <= 0 || money > balance) {System.out.println("# Error, The account of consume need greater than 0 and less than " + balance);} else {break;}}balance -= money;System.out.print("# The description of consume is:");note = scanner.next();details += "\nConsume: -" + money + "\tTime:" + sdf.format(date) + "\tBalance:" + balance + "\tNote:" + note;}public void exit() {//                    enter inwhile (true) {System.out.println("# Are sure you want exit?(y\\n)");exit = scanner.next();if (exit.equals("y") || exit.equals("n")) {break;} else {System.out.println("# Error, please enter again!");}}
//                    exit or notif (exit.equals("y")) {loop = false;System.out.println("=========== Exit ===========");}}
}

package smallchange;public class Test {public static void main(String[] args) {SmallChangeOOP smallChangeOOP = new SmallChangeOOP();smallChangeOOP.mainMenu();}
}

参考资料

[1] 【零基础 快速学Java】韩顺平 零基础30天学会Java
[2]
[3]