Who can help me? I don’t understand why it doesn’t work

Question

import java.util.Scanner;
class Main {
public static void main(String[] args) {
Scanner read = new Scanner(System.in);
double saving = read.nextDouble();
double checking = read.nextDouble();

Account savingAcc = new SavingAcc(saving);
Account checkingAcc = new CheckingAcc(checking);

System.out.println(savingAcc.getIncome());
System.out.println(checkingAcc.getIncome());
}
}
class Account {

private double amount;

public Account(double amount) {
this.amount = amount;
}

public double getAmount() {
return amount;
}

public double getIncome() {
return 0;
}
}

class SavingAcc extends Account {

public SavingAcc(double amount) {
super(amount);
amount = super.getAmount();
}
//Переопределите метод для сберегательного счета
public double getIncome() {
return amount + amount * 0.2;
}
}
class CheckingAcc extends Account {

public CheckingAcc(double amount) {
super(amount);
amount = super.getAmount();
}
//Переопределите метод для чекового счета
public double getIncome() {

return amount + amount * 0.05;
}
}

}

Answer 1

Natalia Zvezdina fixed it for you hope it all makes sense now 😊

https://code.sololearn.com/cba2UmyY6zVq/?ref=app

Answer 2

Natalia Zvezdina your welcome, super.getAmount(); is just fetching the current value of "amount" field in super..

if amount wasnt private then you could just use variable "amount" like you would any inherited variable.

Answer 3

Natalia Zvezdina if you look at the original code there was an extra brace -> } <- at the bottom of your code which I removed, this was causing the no output screen

Answer 4

You can also define
protected double amount instead of private.
In this way you don't need to use super.getAmount(), you can access it directly

this.amount.. etc

like this :
https://code.sololearn.com/cmQzzS69hiWd/?ref=app

Answer 5

Natalia Zvezdina in programming it either works or it doesn't it never somtimes works, super class field amount is declared private so is not inherited by the derived class,

So "this.amount" in constructor is wrong as amount doesn't exist in CheckingAcc due to private access in superClass

You shouldn't really need to create another variable for amount as you can retrieve it through getters and setters which makes your code secure.

so my advice is remove amount in extending classes and replace returns with this.....

return super.getAmount+super.getAmount*5;

Answer 6

what’ the ***uuuck. i wrote the same, but my sololearn app doesn’t output and your programm output all wright)))

Answer 7

ooh, yes. Now it works. Thank you a lot.
but i don’t understand why should i only write super.getAmount() in return ?

Answer 8

when i define a new one in subclasses it doesn’t work all the same

Answer 9

Use a different name then..
What not working? What is your expected output for a sample input..? or
Define new one and use
this.amount=super.getAmount();

Answer 10

thank you for help, but i’ve replaced return and programm doesn’t output anything. it seem to me that somethhing more wrong is with extending classes

Answer 11

import java.util.Scanner;
class Main {
public static void main(String[] args) {
Scanner read = new Scanner(System.in);
double saving = read.nextDouble();
double checking = read.nextDouble();

Account savingAcc = new SavingAcc(saving);
Account checkingAcc = new CheckingAcc(checking);

System.out.println(savingAcc.getIncome());
System.out.println(checkingAcc.getIncome());
}
}
class Account {

double amount;

public Account(double amount) {
this.amount = amount;
}

public double getAmount() {
return amount;
}

public double getIncome() {
return 0;
}
}

class SavingAcc extends Account {

public SavingAcc(double amount) {
super(amount);
}
//Переопределите метод для сберегательного счета
public double getIncome() {
amount = amount + amount * 0.2;
return amount;
}
}
class CheckingAcc extends Account {

public CheckingAcc(double amount) {

Answer 12

It simply, then u think. But don't forget about access double amount in class Account

Answer 13

The amount variable in Account class has private access so you cant use it derived or sub classes...

so define a new one in subclasses..