我正在为我的 java 类创建一个银行账户程序，该程序应该管理多达 5 个不同的银行账户。该程序必须允许创建一个新帐户，我已经完成，允许存款和取款，这也已完成，我无法工作的 2 个部分是 1:银行最多只能有 5 个帐户，所以如果a 6th is trying to be created,一条消息说已经创建了5个，2:其中一个选项必须打印出银行活期账户的所有账户余额。
这是我目前的代码:
import java.util.Scanner;
public class Bankapp {
public static void main(String[] args) {
Scanner s = new Scanner(System.in);
Bank myBank = new Bank();
int user_choice = 2;
do {
//display menu to user
//ask user for his choice and validate it (make sure it is between 1 and 6)
System.out.println();
System.out.println("1) Open a new bank account");
System.out.println("2) Deposit to a bank account");
System.out.println("3) Withdraw to bank account");
System.out.println("4) Print account balance");
System.out.println("5) Quit");
System.out.println();
System.out.print("Enter choice [1-5]: ");
user_choice = s.nextInt();
switch (user_choice) {
case 1:
System.out.println("Enter a customer name");
String cn = s.next();
System.out.println("Enter a opening balance");
double d = s.nextDouble();
System.out.println("Account was created and it has the following number: " + myBank.openNewAccount(cn, d));
break;
case 2: System.out.println("Enter a account number");
int an = s.nextInt();
System.out.println("Enter a deposit amount");
double da = s.nextDouble();
myBank.depositTo(an, da);
break;
case 3: System.out.println("Enter a account number");
int acn = s.nextInt();
System.out.println("Enter a withdraw amount");
double wa = s.nextDouble();
myBank.withdrawFrom(acn, wa);
break;
case 4: System.out.println("Enter a account number");
int anum = s.nextInt();
myBank.printAccountInfo(anum);
break;
case 5:
System.out.println("Here are the balances " + "for each account:");
case 6:
System.exit(0);
}
}
while (user_choice != '6');
}
static class Bank {
private BankAccount[] accounts; // all the bank accounts at this bank
private int numOfAccounts = 5; // the number of bank accounts at this bank
// Constructor: A new Bank object initially doesn’t contain any accounts.
public Bank() {
accounts = new BankAccount[5];
numOfAccounts = 0;
}
// Creates a new bank account using the customer name and the opening balance given as parameters
// and returns the account number of this new account. It also adds this account into the account list
// of the Bank calling object.
public int openNewAccount(String customerName, double openingBalance) {
BankAccount b = new BankAccount(customerName, openingBalance);
accounts[numOfAccounts] = b;
numOfAccounts++;
return b.getAccountNum();
}
// Withdraws the given amount from the account whose account number is given. If the account is
// not available at the bank, it should print a message.
public void withdrawFrom(int accountNum, double amount) {
for (int i =0; i<numOfAccounts; i++) {
if (accountNum == accounts[i].getAccountNum() ) {
accounts[i].withdraw(amount);
System.out.println("Amount withdrawn successfully");
return;
}
}
System.out.println("Account number not found.");
}
// Deposits the given amount to the account whose account number is given. If the account is not
// available at the bank, it should print a message.
public void depositTo(int accountNum, double amount) {
for (int i =0; i<numOfAccounts; i++) {
if (accountNum == accounts[i].getAccountNum() ) {
accounts[i].deposit(amount);
System.out.println("Amount deposited successfully");
return;
}
}
System.out.println("Account number not found.");
}
// Prints the account number, the customer name and the balance of the bank account whose
// account number is given. If the account is not available at the bank, it should print a message.
public void printAccountInfo(int accountNum) {
for (int i =0; i<numOfAccounts; i++) {
if (accountNum == accounts[i].getAccountNum() ) {
System.out.println(accounts[i].getAccountInfo());
return;
}
}
System.out.println("Account number not found.");
}
public void printAccountInfo(int accountNum, int n) {
for (int i =0; i<numOfAccounts; i++) {
if (accountNum == accounts[i].getAccountNum() ) {
System.out.println(accounts[i].getAccountInfo());
return;
}
}
System.out.println("Account number not found.");
}
}
static class BankAccount{
private int accountNum;
private String customerName;
private double balance;
private static int noOfAccounts=0;
public String getAccountInfo(){
return "Account number: " + accountNum + "\nCustomer Name: " + customerName + "\nBalance:" + balance +"\n";
}
public BankAccount(String abc, double xyz){
customerName = abc;
balance = xyz;
noOfAccounts ++;
accountNum = noOfAccounts;
}
public int getAccountNum(){
return accountNum;
}
public void deposit(double amount){
if (amount<=0) {
System.out.println("Amount to be deposited should be positive");
} else {
balance = balance + amount;
}
}
public void withdraw(double amount)
{
if (amount<=0){
System.out.println("Amount to be withdrawn should be positive");
}
else
{
if (balance < amount) {
System.out.println("Insufficient balance");
} else {
balance = balance - amount;
}
}
}
}//end of class
程序运行正常，我只需要添加这两个选项，就不能使它们正常工作，我该怎么做呢？此外，如果尚未创建帐户，选项 3 和 4 将不起作用。提前致谢。
更新:这是我尝试过的方法，我不断收到此方法必须返回类型为 int 的错误。
public int openNewAccount(String customerName, double openingBalance) {
if(numOfAccounts > 5)
{
System.out.println("5 accounts already exist");
}
else
{
BankAccount b = new BankAccount(customerName, openingBalance);
accounts[numOfAccounts] = b;
numOfAccounts++;
return b.getAccountNum();
}
}
更新 2:我添加了一个返回声明，现在当它运行时，它会开立第 5 个账户，但对于第 5 个账户之后的每个账户，它只是说账户号码再次为 5，而不是不开账户。
public int openNewAccount(String customerName, double openingBalance) {
if(numOfAccounts > 5)
{
System.out.println("5 accounts already exist");
}
else
{
BankAccount b = new BankAccount(customerName, openingBalance);
accounts[numOfAccounts] = b;
numOfAccounts++;
return b.getAccountNum();
}
return numOfAccounts;
}
最佳答案
很简单。创建一个大小为 5 的列表，并在创建用户时将帐户添加到该列表中。在添加之前检查列表大小是否 <= 5。如果是，则继续添加帐户，否则抛出错误
对于选项 2，只需遍历列表并显示结果
关于java - 银行账户Java程序，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/30066881/