好的，这是最新的。我正在制作一个简单的银行计划。
这就是我想要做的，请注意我的帐户类（a1，a2，a3）的变量
这完全没问题，但不适合我想做的事情。 在切换案例中，我希望能够让用户在帐户下输入名称并能够对其进行编辑。
现在，我知道我是否基本上这样做了：
Account AccountObject = new Account ();
balance.put (sc.nextLine(), AO.addFunds)
然后我会有单独的用户，但资金基本上都是一样的。我如何将它们分开*
我知道一旦我弄清楚如何做到这一点，我将继续进行更复杂的项目。
import java.util.Hashtable;
import java.util.Scanner;
class Data {
public static void main(String args[]) {
Hashtable<String, Double> balance = new Hashtable<String, Double>();
Scanner sc = new Scanner(System.in);
Scanner sa = new Scanner(System.in);
boolean quit = false;
boolean quit2 = false;
// Create account variables
Account a1 = new Account();
Account a2 = new Account();
Account a3 = new Account();
Account a4 = new Account();
Account a5 = new Account();
// Add funds to variables in Hashtable
balance.put(sc.nextLine(), a1.addFunds());
balance.put(sc.nextLine(), a2.addFunds());
balance.put(sc.nextLine(), a3.addFunds());
balance.put(sc.nextLine(), a4.addFunds());
balance.put(sc.nextLine(), a5.addFunds());
do {
System.out.println("Menu: \n 1: Check balance\n 2: Add funds\n 3: Withdraw funds\n 4: Quit");
int input = sa.nextInt();
switch (input) {
case 1:
System.out.println(balance.get(sc.nextLine()));
break;
case 2:
System.out.println(balance.put(sc.nextLine(), a1.addFunds()));
break;
case 3:
System.out.println(balance.put(sc.nextLine(), a1.withdrawFunds(sa.nextDouble())));
break;
case 4:
quit = true;
break;
}
} while(!quit);
System.out.println("Exiting menu");
}
}
帐户类
import java.util.Scanner;
public class Account {
int balance;
String name;
public double addFunds() {
Scanner sa = new Scanner(System.in);
double amount = sa.nextDouble();
balance += amount;
return balance;
}
public String Acct(String names) {
Scanner sc = new Scanner(System.in);
name = names;
return name;
}
public double withdrawFunds(double amount) {
balance -= amount;
return balance;
}
public String toString() {
return String.format("Balance: %n", balance);
}
}
答案 0 :(得分：0)
您应该创建一个帐户类，它是帐户的模型。我建议你不要在Account类中处理用户输入。
帐户类
public class Account {
private String name;
private int balance;
public Account(String name, int startBalance) {
this.name = name;
this.balance = startBalance;
}
public void addFunds(int amount) {
if (amount < 0) {
throw new IllegalArgumentException("Amount must be absolute");
}
this.balance += amount;
}
public void withdrawFunds(int amount) {
if (amount < 0) {
throw new IllegalArgumentException("Amount must be absolute");
}
else if (amount > this.balance) {
throw new IllegalArgumentException("You don't have that, so you cannot grab that.");
}
this.balance -= amount;
}
public String getName() {
this.name;
}
public int getBalance() {
return this.balance;
}
}
现在，如果需要，您可以创建一些帐户并将其添加到ArrayList<Account>。我不知道为什么你会使用HashMap：如果你只有一个包含所有Account个对象的列表，你就拥有了所需的所有信息。
ArrayList<Account> accounts = new ArrayList<Account>();
Scanner sc = new Scanner(System.in);
您可以像以下一样实现用户输入：
private static ArrayList<Account> accounts = new ArrayList<Account>();
private static Scanner sc = new Scanner(System.in);
public static void main(String[] args) {
initializeSomeBankAccounts();
displayUI();
}
private static void initializeSomeBankAccounts() {
for (int i = 0; i < 2; i++) {
System.out.print("Insert " + (i > 0 ? "another " : "") + "account name: ");
String name = sc.nextLine();
System.out.print("Insert start balance: ");
int startBalance = sc.nextInt();
sc.nextLine();
// Create a new account using the user input
Account account = new Account(name, startBalance);
// Add the account to our list with accounts.
accounts.add(account);
}
}
public static void displayUI() {
boolean quit = false;
while (!quit) {
// Show a menu with the available actions
System.out.println("Menu: \n 1: Check balance\n 2: Add funds\n 3: Withdraw funds\n 4: Quit");
int action = sc.nextInt();
sc.nextLine();
Account account;
// Since we ask the user to insert a right account name, we can
// guarantee that the variable 'account' contains an Account
// object.
switch (action) {
case 1:
account = askAccount();
System.out.println(account.getBalance());
break;
case 2:
account = askAccount();
System.out.print("Amount: ");
int amount = sc.nextInt();
account.addFunds(amount);
break;
case 3:
account = askAccount();
System.out.print("Amount: ");
amount = sc.nextInt();
account.withdrawFunds(amount);
break;
case 4:
quit = true;
break;
}
}
}
private static Account askAccount() {
System.out.println("Which account? ");
Account account = null;
boolean accountFound = false;
// Now the user has to input a valid account name, we're going to
// search for that account name in the list. If it is found, we
// have the whole Account object stored into the variable 'account'.
// Otherwise, if it is not found, then we repeat to ask to insert
// an account name, until a account name is given which is present
// in our list.
while (!accountFound) {
String accountName = sc.nextLine();
account = searchAccount(accountName);
if (account == null) {
System.out.println("Account not found. Insert another account:");
}
else {
accountFound = true;
}
}
return account;
}
/**
* Searches an account from our list of all accounts.
*
* @param name The name to search for.
* @return The account if found, or null otherwise.
*/
private static Account searchAccount(String name) {
for (Account account : accounts) {
if (account.getName().equals(name)) {
return account;
}
}
return null;
}
我也有一些建议：
quit2。您可能想要删除它们。Scanner;一个就足够了，因为您可以在同一台扫描仪上同时拨打nextLine()和nextInt()。AccountObject。在Java中，它是允许的，但Java命名约定规定应该使用小写字母启动变量。Hashtable，但建议您使用HashMap<Key, Value>。