creditcard.java

java实现的已一个模拟信用卡的程序

// 信用卡帐户
public class CreditCard {
	// 信用卡帐户的属性
	private double maxOverdraft;	// 透支限额
	private double balance;  		// 存款余额

	// 构造方法，将透支限额maxOverdraft设置为max
	public CreditCard(double max) {
		maxOverdraft = max;
		if (max >= 1000)  balance = 100;
		else  balance = 0;
	}

	// 向帐户中存款，存款金额为amount
	public void deposit(double amount) {
		balance = balance + amount;
	}

	// 从帐户中取款，取款金额为amount；取款成功返回true，否则返回false
	public boolean withdraw(double amount) {
		if (amount <= balance + maxOverdraft) {
			balance = balance - amount;
			return true;
		} else  return false;
	}

	// 查询帐户的当前余额
	public double getBalance() {
		return balance;
	}
}