Java 练习(super练习)

银行账号，取钱，存钱，透支练习

Account.java

package com.klvchen.exer2;

public class Account {
	
	private int id;
	private double balance;
	private double annualInterestRate;
	
	public Account(int id, double balance, double annualInterestRate) {
		this.id = id;
		this.balance = balance;
		this.annualInterestRate = annualInterestRate;
	}

	public int getId() {
		return id;
	}

	public void setId(int id) {
		this.id = id;
	}

	public double getBalance() {
		return balance;
	}

	public void setBalance(double balance) {
		this.balance = balance;
	}

	public double getAnnualInterestRate() {
		return annualInterestRate;
	}

	public void setAnnualInterestRate(double annualInterestRate) {
		this.annualInterestRate = annualInterestRate;
	}
	
	//返回月利率
	public double getMonthlyInterest() {
		return annualInterestRate / 12;
	}
	
	//取钱
	public void withdraw(double amount) {
		if(balance >= amount ) {
			balance -= amount;
			return;
		}
		System.out.println("余额不足");
	}
	
	//存钱
	public void deposit(double amount) {
		if(amount > 0) {
			balance += amount;
		}
	}
	

}

AccountTest.java

package com.klvchen.exer2;

public class AccountTest {
	public static void main(String[] args) {
		
		Account acct = new Account(1122, 20000, 0.045);
		
		acct.withdraw(30000);
		System.out.println("您的账户余额为： " + acct.getBalance());
		acct.withdraw(2500);
		System.out.println("您的账户余额为： " + acct.getBalance());
		acct.deposit(3000);
		System.out.println("您的账户余额为： " + acct.getBalance());
		
		System.out.println("月利率为: " + (acct.getMonthlyInterest() * 100 ) + "%");
	}
}

CheckAccount.java

package com.klvchen.exer2;

public class CheckAccount extends Account {
	private double overdraft;   //可透支限额

	public CheckAccount(int id, double balance, double annualInterestRate, double overdraft) {
		super(id, balance, annualInterestRate);
		this.overdraft = overdraft;
		
	}
	
	public double getOverdraft() {
		return overdraft;
	}

	public void setOverdraft(double overdraft) {
		this.overdraft = overdraft;
	}

	@Override
	public void withdraw(double amount) {
		if(getBalance() >= amount) {
			super.withdraw(amount);
		}else if(overdraft >= amount - getBalance()) { //透支额度+余额足够消费
			
			overdraft -= (amount - getBalance());
			
			//setBalance(0);
			//或
			super.withdraw(getBalance());
		}else {
			System.out.println("超过可透支限额！");
		}
	}
}

CheckAccountTest.java

package com.klvchen.exer2;

public class CheckAccountTest {
	public static void main(String[] args) {
		
		CheckAccount acct = new CheckAccount(1122, 20000, 0.045, 5000);
		
		acct.withdraw(50000);
		System.out.println("您的账号余额为: " + acct.getBalance());
		System.out.println("您的可透支额度为: " + acct.getOverdraft());
		
		System.out.println("***********************************");
		
		acct.withdraw(18000);
		System.out.println("您的账号余额为: " + acct.getBalance());
		System.out.println("您的可透支额度为: " + acct.getOverdraft());
		
		System.out.println("***********************************");
		
		acct.withdraw(3000);
		System.out.println("您的账号余额为: " + acct.getBalance());
		System.out.println("您的可透支额度为: " + acct.getOverdraft());
	}

}

Java 练习(super练习)

运行结果: