面向对象（上）综合练习1：银行存取
账户 Account类
1 package day1_11.exer2; 2 3 //账户 4 public class Account { 5 private double balance;//余额 6 7 public Account(double balance) { 8 this.balance = balance; 9 } 10 //获取余额 11 public double getBalance() { 12 return balance; 13 } 14 15 //存钱 16 public void deposit(double amt) { 17 if (amt > 0) { 18 balance += amt; 19 System.out.println("存入" + amt + "成功"); 20 } 21 } 22 23 //取钱 24 public void withdraw(double amt) { 25 if (balance > amt) { 26 balance -= amt; 27 System.out.println("取出" + amt + "成功"); 28 }else{ 29 System.out.println("取出" + amt + "失败"); 30 } 31 } 32 }
客户 Customer类
1 package day1_11.exer2; 2 //客户 3 public class Customer { 4 private String firstName;//名 5 private String lastName;//姓 6 private Account account;//账户 7 8 public Customer(String f, String l) { 9 this.firstName = f; 10 this.lastName = l; 11 } 12 13 public Customer() { 14 } 15 16 public String getFirstName() { 17 return firstName; 18 } 19 20 public String getLastName() { 21 return lastName; 22 } 23 24 public Account getAccount() { 25 return account; 26 } 27 28 public void setAccount(Account account) { 29 this.account = account; 30 } 31 }
银行 Bank类
1 package day1_11.exer2; 2 3 public class Bank { 4 private Customer[] customers;//存放多个客户的数组 5 private int numberOfCustomer;//记录客户的个数 6 7 public Bank() { 8 customers = new Customer[10]; 9 } 10 11 //添加客户 12 public void addCustomer(String f,String l) { 13 Customer customer = new Customer(f, l); 14 //customers[numberOfCustomer] = customer; 15 //numberOfCustomer++; 16 //简单写法 17 customers[numberOfCustomer++] = customer; 18 } 19 20 //获取客户个数 21 public int getNumberOfCustomer() { 22 return numberOfCustomer; 23 } 24 25 //获取指定位置上的客户 26 public Customer getCustomer(int index) { 27 //return customers[index] 可能报异常 28 if(index >= 0 && index <numberOfCustomer){ 29 return customers[index]; 30 } 31 32 return null; 33 } 34 }
测试 BankTest
1 package day1_11.exer2; 2 3 public class BankTest { 4 public static void main(String[] args) { 5 Bank bank = new Bank(); 6 bank.addCustomer("Davi", "Smith"); 7 //获取客户的个数 8 int numberOfCustomer = bank.getNumberOfCustomer(); 9 System.out.println("客户个数：" + numberOfCustomer); 10 //获取指定位置上的客户 11 Customer customer = bank.getCustomer(numberOfCustomer-1); 12 Account account = new Account(2000); 13 customer.setAccount(account); 14 //存钱100 15 customer.getAccount().deposit(100); 16 //查看余额 17 System.out.println("客户：" + customer.getFirstName() + "的账户余额为：" + customer.getAccount().getBalance()); 18 //取钱2000 19 customer.getAccount().withdraw(2000); 20 //查看余额 21 System.out.println("客户：" + customer.getFirstName() + "的账户余额为：" + customer.getAccount().getBalance()); 22 23 System.out.println("**********************"); 24 25 bank.addCustomer("慕容","上官"); 26 System.out.println("客户个数：" + bank.getNumberOfCustomer()); 27 Customer customer2 = bank.getCustomer(bank.getNumberOfCustomer() - 1); 28 customer2.setAccount(new Account(100)); 29 //存100 30 customer2.getAccount().deposit(100); 31 //查看余额 32 System.out.println("客户：" + customer2.getFirstName() + "的账户余额为：" + customer2.getAccount().getBalance()); 33 //取300 34 customer2.getAccount().withdraw(3000); 35 //查看余额 36 System.out.println("客户：" + customer2.getFirstName() + "的账户余额为：" + customer2.getAccount().getBalance()); 37 } 38 }
运行结果
