修改withdraw 方法

修改withdraw 方法

练习目标－使用有返回值的方法：在本练习里，将修改withdraw方法以返回一个布尔值来指示交易是否成功。

 

 

任务

 

1． 修改Account类

1. 修改deposit 方法返回true（意味所有存款是成功的）。
2. 修改withdraw方法来检查提款数目是否大于余额。如果amt小于balance,则从余额中扣除提款数目并返回true，否则余额不变返回false。

 

2． 在exercise2主目录编译并运行TestBanking程序，将看到下列输出;

 

Creating the customer Jane Smith.

Creating her account with a 500.00 balance.

Withdraw 150.00: true

Deposit 22.50: true

Withdraw 47.62: true

Withdraw 400.00: false

Customer [Smith, Jane] has a balance of 324.88

 

package banking;

public class Account 
{
    //成员属性
    private double balance ;//余额

    // 无参构造
    public Account() 
    {
        
    }
    // 有参构造
    public Account(double balance) 
    {
        this.balance = balance;
    }
    
    // set  get 
    public double getBalance()
    {
        return balance;
    }
    public void setBalance(double balance)
    {
        this.balance = balance;
    }
    

    
    public boolean withdraw1( double amt )
    {
        if(amt>0&&amt<balance==true)
        {
            balance -= amt ;
            System.out.print("Withdraw " + amt+" : ");
            return true ;
        }
        else
        {
            System.out.print("Withdraw " + amt+" : ");
            return false ;
        }
    }
    
    public boolean deposit1( double amt ) 
    {
        if(amt<0)
        {
            System.out.print("Deposit " + amt+" : " );
            return false ;
        }
        else
        {
            balance += amt ;
            System.out.print("Deposit " + amt +" : ");
            return true ;
        }
    }
    
    
    
    
    
}

    Customer cr1 = new Customer( ) ;
        
        cr1.setFirstName("Jane");
        cr1.setLastName("Smith");
        cr1.setBalance(500);
        System.out.println("Creating the customer "+cr1.getFirstName() +" "+cr1.getLastName());
        System.out.println("Creating her account  with  a " +cr1.getBalance()+" balance");
        System.out.println(cr1.withdraw1(150) );
        System.out.println(cr1.deposit1(22.5));
        System.out.println(cr1.withdraw1(47.62));
        System.out.println(cr1.withdraw1(400));
        System.out.println("Customer "+cr1.getLastName()+" "+cr1.getFirstName()+
                                            " has a balance of "+cr1.getBalance());