练习7

package com.atguigu.exercise3;
public class Account {
    //属性
    private double balance;
    //构造器
    public  Account(double init_balance){
  balance = init_balance;
    }
    //方法
    public double getBalance() {
  return balance;
    }
  //存钱
    public void deposit(double amt){
  if(amt > 0){
      balance += amt;
      System.out.println("存钱成功！");
  }
    }
  //取钱
    public void withdraw(double amt){
  if(balance >= amt){
      balance -= amt;
      System.out.println("取钱成功！");
  }else{
      System.out.println("余额不足！");
  }  
    }
}

package com.atguigu.exercise3;
public class Customer {
    //属性
    private String firstName;
    private String lastName;
    private Account account;
    //构造器
    public Customer(String f,String l){
  this.firstName = f;
  this.lastName = l;
    }
    //方法
    public Account getAccount() {
  return account;
    }
    public void setAccount(Account account) {
  this.account = account;
    }
    public String getFirstName() {
  return firstName;
    }
    public String getLastName() {
  return lastName;
    }  
}

package com.atguigu.exercise3;
public class Bank {
    //属性
    private Customer[] customers= new Customer[10];
    ;//存放多个客户
    private int numberOfCustomer;//记录客户的个数
    //构造器
    public Bank(){
//  customers = new Customer[10];
    }
    //方法
  //添加客户
    public void addCustomer(String f,String l){
  Customer cust = new Customer(f,l);
  customers[numberOfCustomer] = cust;
  numberOfCustomer++;
    }
  //获取客户的个数
    public int getNumOfCustomers(){
  return numberOfCustomer;
    }
  //获取指定位置上的客户
    public  Customer getCustomer(int index){
  if(index >= 0 && index < numberOfCustomer){
      return customers[index];
  }
  return null;
    }
}

package com.atguigu.exercise3;
public class BankTest {
    public static void main(String[] args) {
  Bank bank = new Bank();
  bank.addCustomer("Jane", "Smith");
  bank.getCustomer(0).setAccount(new Account(2000));
  bank.getCustomer(0).getAccount().withdraw(500);//取钱
  double banlance = bank.getCustomer(0).getAccount().getBalance();
  System.out.println("客户："+bank.getCustomer(0).getFirstName()+"的账户余额为："+banlance);
    }
}