银行取款测试

Bank.java

public class Bank {
	
	private Customer[] customers;   //存放多个客户的数组
	private int numberOfCustomers;  //记录客户的个数
	
	public Bank() {
		customers = new Customer[10];
	}
	
	//添加客户
	public void addCustomer(String f, String l) {
		Customer cust = new Customer(f, l);
//		customers[numberOfCustomers] = cust;
//		numberOfCustomers++;
		//或
		customers[numberOfCustomers++] = cust;
	}

	//获取客户的个数
	public int getNumOfCustomers() {
		return numberOfCustomers;
	}
	
	//获取指定位置的客户
	public Customer getCustomer(int index) {
		if(index >= 0 && index < numberOfCustomers) {
			return customers[index];
		}
		return null;
	}
	
	
}

Account.java

public class Account {

	private double balance;
	
	public Account(double init_balance) {
		this.balance = init_balance;
	}
	
	public double getBalance() {
		return balance;
	}
	
	//存钱模式
	public void deposit(double amt) {
		if(amt > 0) {
			balance += amt;
			System.out.println("存钱成功");
		}
	}
	
	//取钱模式
	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");
		}
	}
	
}

Customer.java

public class Customer {
	
	private String firstName;
	private String lastName;
	private Account account;
	
	public Customer(String f, String l) {
		this.firstName = f;
		this.lastName = l;
	}

	public Account getAccount() {
		return account;
	}

	public void setAccount(Account account) {
		this.account = account;
	}

	public String getFirstName() {
		return firstName;
	}

	public String getLastName() {
		return lastName;
	}
}

BankTest.java

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);
		
		bank.getCustomer(0).getAccount().getBalance();
		
		double balance = bank.getCustomer(0).getAccount().getBalance();
		System.out.println("客户, " + bank.getCustomer(0).getFirstName() + "的账户余额为: " + balance);
		
		System.out.println("*********************************************");
		bank.addCustomer("靖", "郭");
		
		System.out.println("银行客户的个数为: " + bank.getNumOfCustomers());
	}
	
}

运行结果: