求救,JAVA高手近来看看,在线等 谢谢

[zengwei320]

程序为:

public class Account{
protected double balance;
public Account(double init_balance){
balance=init_balance;
}
public double getBalance(){
return balance;
}
public void deposit(double amt){
if(amt>0){
balance = balance + amt;
System.out.println("deposit success");

}

else System.out.println("deposit false");
}
public void withdraw(double amt) {

if((balance-amt)>0){
balance = balance - amt;
System.out.println("Withdraw success");

}

else System.out.println("Withdraw false");
}
}

class SavingsAccount extends Account{
private double interest_Rate;
public double SavingAccount(double balance,double

interest_rate){

return super.getBalance()*interest_rate;

}
}

提示的错误为:Account(double)in Account cannot be applied to()class SavingsAccount extends Account{

[zoeg]

在SavingsAccount类中增加一个构造器：
public SavingsAccount(double init_balance){
super(init_balance);
}
因为父类没有默认构造器，所以你必须在你的构造器中显式的调用父类构造器

[wangw2004]

由于你的父类中overload了构造函数－－》Account(double)，所以在子类中必须显示的调用这个父类的构造函数 而不能调用默认的构造函数

[trumplet]

给父类Account写个默认的无参构造函数：

public Account(){
balance=0;
}