# Account II URL: **Requirements** 1. **Instance variables:** * `double interestRate`: a double variable indicating the monthly interest rates. For example, if the `interstRate` is 2, it means monthly interest rate is 2%. * `double fee`: a double variable indicating a monthly fee charged to the account, if the balance is below a threshold. * `double threshold`: a double variable indicating the minimum balance required to avoid the monthly fee. 2.**Static Variable:** * `accountCount`: an integer static variable to keep track of the number of Account instances created. 3.**Constructors:** Since you add three instance variables, so you should modify your constructors like this:public Account(String accountHolder, String accountNumber,double balance, double interestRate, double fee, double threshold) {...}Each time an new account is created, `accountAcount` should increase by 1. 4.**New Methods:** * `public static int getAccountCount()`: returns the current value of `accountCount.` * `private void applyInterest()`: applies a monthly interest rate to the balance. * `private void chargeFee()`: charges a fee if the balance is below a specified threshold. * `public void passMonth()`: simulates the passage of a month. It will first apply interest to the balance of the account. If the new balance is below threshold, it will be charge a fee. * For example, is the current balance is 100, monthly interest rate is 10%, threshold is 200, and the fee is 5. * When a month passed, the balance will get interests, become 100 + 100\*10%=110.0. Since it is below threshold(200), the account will be charged a ¥5 fee. * So the account should have ¥105.0 after the month passed. `applyInterest` and `chargeFee` should be private, meaning they can only be called within the Account class.`Hint: applyInterest() and chargeFee() is triggered monthly, so they should be only called by passMonth().` 1. 4.The following table contains a code execution sequence and the corresponding results: | Statement of Expression | Return Value | Explanation | | -------------------------------------------------------------------- | ------------ | --------------------------------------------------------------------------------------------------------------------------- | | Account a1 = new Account("John Doe", "12345678", 100, 10, 20, 200); | N/A | Create account a1 with initial balance of ¥100, 10% monthly interest, ¥20 fee, ¥200 threshold. | | Account.getAccountCount(); | 1 | Returns the total number of accounts created after a1's creation. | | a1.deposit(150); | true | Deposit of ¥150 to a1. | | a1.getBalance(); | 250.0 | Balance in a1 after deposit. | | a1.passMonth(); | N/A | Simulate a month passing for a1. | | a1.getBalance(); | 275.0 | Balance in a1 after a month, with interest. There is no fee charged, since 275.0 is larger than 200. | | a1.withdraw(130); | true | Withdraw ¥130 from a1. | | a1.getBalance(); | 145.0 | Balance in a1 after withdrawal. | | a1.passMonth(); | N/A | Simulate another month passing for a1. | | a1.getBalance(); | 139.5 | Balance in a1 after second month, with interest applied. There is a ¥10 fee charged, so the balance is 145\*1.1-20 = 139.5。 | | Account a2 = new Account("Jane Smith", "87654321", 50, 20, 10, 200); | N/A | Create account a2 with initial balance of ¥50, 20% monthly interest, ¥10 fee, ¥200 threshold. | | Account.getAccountCount(); | 2 | Returns the total number of accounts created after a2's creation. | | a2.deposit(50); | true | Deposit of ¥50 to a2. | | a2.getBalance(); | 100.0 | Balance in a2 after deposit. | | a2.passMonth(); | N/A | Simulate a month passing for a2. | | a2.getBalance(); | 110.0 | Balance in a2 after a month, with interest and fee charged. The balance is 100\*1.2-10 = 110.0. | | a2.withdraw(20); | true | Withdraw ¥20 from a2. | | a2.getBalance(); | 90.0 | Balance in a2 after withdrawal. | | a2.passMonth(); | N/A | Simulate another month passing for a2. | | a2.getBalance(); | 98.0 | Balance in a2 after second month, with interest and fee charged. The balance is 90\*1.2-10 = 98.0. | ### FULL SCORE * Zhu Qixin * Dong Ruoxuan * He Yuhan * Jin Xuanyu * Lin Jiaxin * Luo Rui * Wang Jiaxi * Zhang Wenyuan * Zheng Hao * Zhu Yi * Liu Xintong * Zhang Tianyu * Ding Chengtian * Ni Jiachen * Zhang Xiaowen ### ALMOST THERE * Wang Yueqi * Hu Yuqin * Lyu Jiajia * Chen Sihan * Li Jiakang --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. 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