Java继承与多态编程题目

Question

类BankAccount定义了账号accountNumber、余额balance，子类SavingsAccount 定义了利率interetRate。 （1）设计完整的继承层次结构UML类图，并转换为Java代码。 （2）编写测试类SavingsAccountTest，创建一储蓄账户，使用类SavingsAccount的构造函 数初始化账号、余额、利率，语句如下： SavingsAccount savingsAccount = new SavingsAccount("95588", 8000, 0.30);

Answer 1

//BankAccount类
public class BankAccount {
    private String accountNumber;
    private double balance;
    public BankAccount(){}
    public BankAccount(String accountNumber, double balance) {
        this.accountNumber = accountNumber;
        this.balance = balance;
    }
}


//SavingsAccount类
public class SavingsAccount extends BankAccount{
    private double interetRate;

    public SavingsAccount(String accountNumber, double balance, double interetRate) {
        super(accountNumber, balance);
        this.interetRate = interetRate;
    }
}


//SavingsAccountTest测试类
public class SavingsAccountTest {
    public static void main(String[] args) {
        SavingsAccount savingsAccount = new SavingsAccount("95588", 8000, 0.30);
    }
}