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());
}
}