Question

java定义一个类实现银行账户的概念。

包括的属性有“帐号”和“存款余额”，包括的方法有“存款”、“取款”、“查询余额”和“显示帐号”。编写一个测试类，创建两个不同的账户类对象，并分别完成存款、取款、查询余额、显示帐号等操作。

Answer 1

public class BankAccount {

String account ;
int account_num;

//构造函数
public BankAccount(String account,int account_num){
this.account=account;
this.account_num=account_num;
}
//存钱
public String addNum(int num){
account_num= account_num+num;
return "存钱成功";
}

//取钱
public String getNum(int num){
String result;
if(account_num>num){
account_num =account_num-num;
result="取钱成功";
}else{
result="账户余额不足，还剩"+account_num;
}
return result;
}

//显示余额
public String displayNum(){
return "账户余额："+account_num;
}

//显示账号
public String displayAccount(){
return "账户："+account;
}

public static void main(String[] args){
BankAccount lucy = new BankAccount("lucy",100);
BankAccount jack = new BankAccount("jack",50);
//显示他们各自的余额
System.out.println("===显示他们各自的余额===");
System.out.println("lucy:"+lucy.displayNum());
System.out.println("jack:"+jack.displayNum());
//存钱取钱
System.out.println("===存钱取钱===");
System.out.println("lucy取50:"+lucy.getNum(50));
System.out.println("jack存200:"+jack.addNum(200));
//显示账户 显示余额
System.out.println("===存钱取钱===");
System.out.println(lucy.displayAccount()+""+lucy.displayNum());
System.out.println(jack.displayAccount()+""+jack.displayNum());

}

}

运行结果：
===显示他们各自的余额===
lucy:账户余额：100
jack:账户余额：50
===存钱取钱===
lucy取50:取钱成功
jack存200:存钱成功
===存钱取钱===
账户：lucy账户余额：50
账户：jack账户余额：250

Answer 2

abstract class BankCard {

protected String name;
protected String cardNo;
protected double money;

public BankCard(String name, String cardNo, double money) {
super();
this.name = name;
this.cardNo = cardNo;
this.money = money;
}

public String getName() {
return name;
}
public String getCardNo() {
return cardNo;
}
public double getMoney() {
return money;
}

public abstract void unputMoney(int someMoney);

public void putMoney(int someMoney) {
this.money += someMoney;
}
}