腾讯地图提交商户标注:JAVA中怎样NEW同一个类的两个方法??~!

来源:百度文库 编辑:高校问答 时间:2024/04/28 22:45:23
JAVA中怎样NEW同一个类的两个方法??~!
为什么我有问题呢??帮忙看看
abstract class Account
{
String name;
double balance;
double amt;
Account(String name,double balance)
{
this.name=name;
this.balance=balance;
}
abstract void withdraw(double amt);
}
class SavingsAccount extends Account
{
double interestRate;
SavingsAccount(String name,double balance,double interestRate)
{
super(name,balance);
this.interestRate=interestRate;
}
void withdraw(double amt)
{
balance-=amt;
System.out.println("取款:"+amt);
}
void show()
{
System.out.println(name+"初始余额为:"+balance);
}
}
public class AccountTest
{
public static void main(String args[])
{
System.out.println("储蓄帐户详细信息");
System.out.println("------------------------------");
SavingsAccount savObj=new SavingsAccount("John",500.0,0.04);
savObj.show();
SavingsAccount savObj1=new withdraw(200.0);
}
}

你首先要了解NEW出来的是一个对象,而这个对象包括二个方法,
要调用方法,使用“对象名.方法名(参数)”

abstract class Account {
String name;
double balance;
double amt;
Account(String name,double balance)
{
this.name=name;
this.balance=balance;
}
abstract void withdraw(double amt);
}
class SavingsAccount extends Account
{
double interestRate;
SavingsAccount(String name,double balance,double interestRate)
{
super(name,balance);
this.interestRate=interestRate;
}
void withdraw(double amt)
{
balance-=amt;
System.out.println("取款:"+amt);
}
void show()
{
System.out.println(name+"初始余额为:"+balance);
}
}
public class ex1
{
public static void main(String args[])
{
System.out.println("储蓄帐户详细信息");
System.out.println("------------------------------");
SavingsAccount savObj=new SavingsAccount("John",500.0,0.04);
savObj.show();
savObj.withdraw(200.0);
}
}

你写的有两个类,一个是父类,一个是子类.
withdraw(200,0)只是你的子类的一个方法,不能用new;
你只需要创建一个对象,然后调用withdraw这个方法就行了.
我改后的代码如下,你可以试一下
public static void main(String args[])
{
System.out.println("储蓄帐户详细信息");
System.out.println("------------------------------");
SavingsAccount savObj=new SavingsAccount("John",500.0,0.04);
savObj.show();
savObj.withdraw(200.0);
System.out.println("取款后:");
savObj.show();
}

SavingsAccount savObj=new SavingsAccount("John",500.0,0.04);

SavingsAccount savObj1=new withdraw(200.0);
这只是一个类实例化了两个对象
其中savObj对象要通过SavingsAccount("John",500.0,0.04)构造方法来 进行实例化
而savObj1对象通过withdraw(200.0)构造方法来实现