Help for write Bank application in Java

[clapton]

Hi.
I'm a student and I need write a programe bank application in java .
I must write a program that the customer could withdraw and deposit from his account.I need a few class?
my professor said me that it's very simple but it's dificullte for me.
you can help me for write it program.

[Philippe.Lahaie]

you can help me for write it program.

No.
We can help you understand what the errors are in the program that you write.

[clapton]

I wrote this program,but When I withdraw from my account and again I deposit there isn't balance correct,
you can help me?

import java.util.Scanner;

 

public class BankAccount {

      public static void main(String[] args) {
      Scanner clapton=new Scanner(System.in);
      int x;
      float balance = 0;
      boolean quit=false;
       do {
                 System.out.println("1. Deposit money");
                 System.out.println("2. Withdraw money");
                 System.out.println("3. Check balance");
                 System.out.print(" 0 to quit: "); 
                 System.out.println("enter your choice :");
      x=clapton.nextInt();

     if (x==1) {
        float amount;
        System.out.println(" enter your deposit money :");
        amount=clapton.nextFloat();
        balance =+ amount;
}
else if (x==2) {
        float amount;
        System.out.println(" enter your Withdraw money :");
        amount=clapton.nextFloat();
        balance = -amount;
}
else if (x==3) {
        System.out.println("your balance :" + balance );
}
else if (x==0) {
        quit=true;
}
else {
        System.out.println("wrong choice");
}

}  while (!quit);
        System.out.println("bye");
}
}

[stultuske]

what do you mean: isn't correct.

replace
balance = -amount;
balance -= amount;

the same with
balance =+ amount
should be
balance += amount

if you want lesser lines of code: you don't need all those amount variables, you can just put
balance += clapton.nextFloat();

[clapton]

what do you mean: isn't correct.

replace
balance = -amount;
balance -= amount;

the same with
balance =+ amount
should be
balance += amount

if you want lesser lines of code: you don't need all those amount variables, you can just put
balance += clapton.nextFloat();

thanks a lot.

[stultuske]

if you need to use classes (OO design) you can create a class
BankAccount
which has an instance variable amount
and has methods:
withDraw which takes a parameter -> amountToWithDraw
deposit -> amountToAdd
checkBalance -> which takes no parameters, but which returns the value in the instance variable amount