它要求用户输入一个ID，然后检查ID是否正确，并显示具有四个选项的主菜单。
问题在于，当用户选择一个选项时，程序结束了..但是我需要的是，一旦系统启动，它就永远不会停止，直到用户选择4（这是退出选项），然后重新开始
（游戏：ATM机）使用在编程练习9.7中创建的Account类模拟ATM机。在ID为0、1 、、的数组中创建十个帐户。 。 。 ，9和初始余额$ 100。系统提示用户输入编号。如果输入的ID错误，请要求用户输入正确的ID。接受ID后，将显示主菜单，如示例运行中所示。您可以输入选项1查看当前余额，选择2提取资金，选择3存入资金，选择4退出主菜单。退出后，系统将再次提示输入ID。因此，一旦系统启动，它就不会停止。
import java.util.Scanner;
public class Account {
private int id;
private double balance;
private static double annualIntrestRate;
private java.util.Date dateCreated;
public Account() {
}
public Account(int id) {
this.id = id;
balance = 100;
dateCreated = new java.util.Date();
}
public void setAnnualIntrest(double intrest) {
annualIntrestRate = intrest;
}
public void setBalance(double newBalance) {
balance = newBalance;
}
public void setID(int newID) {
id = newID;
}
public double getBalance() {
return balance;
}
public int getID() {
return id;
}
public java.util.Date getDate() {
return dateCreated;
}
public static double getMonthlyIntrestRate() {
return ((annualIntrestRate / 12) / 100);
}
public double getMonthlyIntrest() {
return (balance * getMonthlyIntrestRate());
}
public double withDraw(double withDrawAmount) {
return balance = balance - withDrawAmount;
}
public double deposit(double depositeAmount) {
return balance = balance + depositeAmount;
}
public static void main(String[] args) {
Account[] accounts = new Account[10];
for (int i = 0; i < accounts.length; i++) {
accounts[i] = new Account(i);
}
Scanner input = new Scanner(System.in);
System.out.print("Enter an ID: ");
int enteredID = input.nextInt();
while (enteredID != accounts[enteredID].getID()) {
System.out.print("enter correct id!");
enteredID = input.nextInt();
}
if (enteredID == accounts[enteredID].getID()) {
System.out.println("Main Menu: ");
System.out.println("1: check balance");
System.out.println("2: withdraw");
System.out.println("3: deposit");
System.out.println("4: exit");
System.out.print("Enter a choice: ");
int choice = input.nextInt();
if (choice == 1) {
System.out.println("The balance is: " + accounts[enteredID].getBalance());
} else if (choice == 2) {
System.out.print("Enter withdraw amount: ");
int withdrawAmount = input.nextInt();
accounts[enteredID].withDraw(withdrawAmount);
} else if (choice == 3) {
System.out.print("Enter deposit amount: ");
int depositAmount = input.nextInt();
accounts[enteredID].deposit(depositAmount);
} else if (choice == 4) {
System.out.print("Enter an ID: ");
enteredID = input.nextInt();
}
}
}
答案 0 :(得分：3)
程序中缺少该问题的两个基本部分：
1）退出后，系统将再次提示输入ID。因此，一旦系统启动，它就不会停止。
这意味着一旦您的main方法中的实际工作开始（第一个“输入id”），就不应在内部停止程序；如果它在终端中运行，则只能通过Ctrl-C来访问；如果它在IDE中运行，则只能通过“停止”按钮来实现。
要实现此目的，您需要一个外部while循环：
while(true) {
// the rest of the code goes in here
}
主要方法中整个“工作”的内容。
2）接受ID后，将显示主菜单，如示例运行中所示。您可以输入选项1来查看当前余额，选择2来取款，选择3来存钱，选择4退出主菜单。
我假设这意味着在输入选项4之前，菜单应该在用户完成任务1、2或3之后一直重新出现，这意味着该部分代码需要使用ANOTHER循环，即：
boolean shouldExit = false;
while (!shouldExit) {
// print menu and do your logic checking when a value is entered.
if (choice == 4) {
shouldExit = true; // This will break out of this loop, and go back to the first "enter an id".
}
}
希望这有助于指导您正确的方向。
答案 1 :(得分：0)
尝试以下代码：
import java.util.Scanner;
public class Account {
private int id;
private double balance;
private static double annualInterestRate;
private java.util.Date dateCreated;
public Account() { }
public Account(int id) {
this.id = id;
this.balance = 100;
this.dateCreated = new java.util.Date();
}
public void setAnnualInterest(double interest) {
annualInterestRate = interest;
}
public void setBalance(double newBalance) {
balance = newBalance;
}
public void setID(int newID) {
id = newID;
}
public double getBalance() {
return balance;
}
public int getID() {
return id;
}
public java.util.Date getDate() {
return dateCreated;
}
public static double getMonthlyInterestRate() {
return ((annualInterestRate / 12) / 100);
}
public double withDraw(double withDrawAmount) {
return balance = balance - withDrawAmount;
}
public double deposit(double depositAmount) {
return balance = balance + depositAmount;
}
public static void main(String[] args) {
Account[] accounts = new Account[10];
for (int i = 0; i < accounts.length; i++) {
accounts[i] = new Account(i);
}
Scanner input = new Scanner(System.in);
System.out.print("Enter an ID: ");
int enteredID;
do {
enteredID = input.nextInt();
if (enteredID <= 9 && enteredID >=0 && enteredID == accounts[enteredID].getID()) {
System.out.println("Main Menu: ");
System.out.println("1: check balance");
System.out.println("2: withdraw");
System.out.println("3: deposit");
System.out.println("4: exit");
do {
System.out.print("Enter a choice: ");
int choice = input.nextInt();
input.nextLine();
if (choice == 1) {
System.out.println("The balance is: " + accounts[enteredID].getBalance());
} else if (choice == 2) {
System.out.print("Enter withdraw amount: ");
int withdrawAmount = input.nextInt();
accounts[enteredID].withDraw(withdrawAmount);
} else if (choice == 3) {
System.out.print("Enter deposit amount: ");
int depositAmount = input.nextInt();
accounts[enteredID].deposit(depositAmount);
} else if (choice == 4) {
System.out.println("Exit");
System.out.println("Enter an ID");
break;
}
} while (true);
}
else{
System.out.print("enter correct id!");
}
}while(true);
}
}
我建议使用switch语句代替if-else梯形图
// same as above code
System.out.print("Enter a choice: ");
int choice = input.nextInt();
input.nextLine();
switch(choice) {
case 1:
System.out.println("The balance is: " + accounts[enteredID].getBalance());
break;
case 2:
System.out.print("Enter withdraw amount: ");
int withdrawAmount = input.nextInt();
accounts[enteredID].withDraw(withdrawAmount);
break;
case 3:
System.out.print("Enter deposit amount: ");
int depositAmount = input.nextInt();
accounts[enteredID].deposit(depositAmount);
break;
case 4:
System.out.println("Exit");
System.out.println("Enter an ID");
break;
}
} while (true);
}
答案 2 :(得分：0)
导入java.util.Scanner;
公共类帐户{
$request->validate([
'ObservationNotes'=>'required',
'ImageUpload.*'=>'image|mimes:jpeg, png, jpg, gif, svg |max:2048'
]);
}