How to convert money to change

Question

trying to convert a entered number into quarters, nickels, dimes, and pennies. Having a few problems:

    public class Coins {
public static void main(String[] args){

private int quarters, dimes, nickels, pennies;

public void CoinsToChange(TotalCoins){
    quarters = (int)(TotalCoins/25);
    TotalCoins %= 25;
    dimes = (int)(TotalCoins/10);
    TotalCoins %= 10;
    nickels = (int)(TotalCoins/5);
    TotalCoins %= 5;
    pennies = (int)(TotalCoins/1);
    TotalCoins %= 1;

    System.out.println("Quarters = " + quarters + "\nDimes = " + dimes + "\nNickels = " + nickels + "\nPennies = " + pennies);
    }
}
    }

and this is my tester class: (im having problems calling the CoinsTotChange method.)

     import java.util.Scanner;

    public class CoinsTester {
    Coins money = new Coins();
    money.CoinsToChange(changeMoney);
    Scanner kybd = new Scanner(System.in);
    int changeMoney = kybd.nextInt();

}

You say you're having problems, but you don't say what the problems are. — Alex W, Jan 15 '14 at 15:19
This "public void CoinsToChange(TotalCoins)" should not even compile in java — user1455836, Jan 15 '14 at 15:27

score 3 · Answer 1 · answered Jan 15 '14 at 15:26

Try changing the order of operations. You typically cannot use an object/variable before it has been declared/instanced.

Coins money = new Coins();
Scanner kybd = new Scanner(System.in);
int changeMoney = kybd.nextInt();
money.CoinsToChange(changeMoney);

score 1 · Answer 2 · answered Jan 15 '14 at 15:36

There are lots of syntax issues but your overall computations are correct. Try something like this:

public class Coins {
    public static void main(String[] args) {
        Scanner kybd = new Scanner(System.in);
        int totalPennies = kybd.nextInt();
        printMoneyAsChange(totalPennies);
    }

    public static void printMoneyAsChange(int pennies) {
        int quarters = pennies / 25;
        pennies %= 25;

        int dimes = pennies / 10;
        pennies %= 10;

        int nickels = pennies / 5;
        pennies %= 5;

        System.out.println(String.format("Quarters = %d\nDimes = %d\nNickels = %d\nPennies = %d", quarters, dimes, nickels, pennies));
    }
}

James Dunn · Answer 3 · 2014-01-15T17:05:17.827

These are the problems:

In your Coins class, you have attempted to wrap everything inside the main method. You need to declare your method and variables separately, and then call them in the main method.
Instead of making a main method in your Coins class, it should be in your tester class.
When you declare a method with parameters, you need to specify the type. So instead of public void CoinsToChange(TotalCoins) it should be public void CoinsToChange(int TotalCoins).
Finally, in your tester class, you were calling money.CoinsToChange(changeMoney) before you declared and assigned changeMoney in int changeMoney = kybd.nextInt(). You need to put that line after it instead of before it.

Making as few changes as possible, I got your code to work like so:

public class Coins {

    private int quarters, dimes, nickels, pennies;

    public void CoinsToChange(int TotalCoins) {
        quarters = (int) (TotalCoins / 25);
        TotalCoins %= 25;
        dimes = (int) (TotalCoins / 10);
        TotalCoins %= 10;
        nickels = (int) (TotalCoins / 5);
        TotalCoins %= 5;
        pennies = (int) (TotalCoins / 1);
        TotalCoins %= 1;

        System.out.println("Quarters = " + quarters + "\nDimes = " + dimes
                + "\nNickels = " + nickels + "\nPennies = " + pennies);
    }
}

Tester class:

 import java.util.Scanner;

    public class CoinsTester {

        public static void main(String[] args) {
            Coins money = new Coins();
            Scanner kybd = new Scanner(System.in);
            int changeMoney = kybd.nextInt();
            money.CoinsToChange(changeMoney); // This line needs to be at the bottom
        }
    }

NOTE: Some of the other answers also give you good suggestions having to do with better variable names and use of String formatting. It would be good to take their advice. I specifically wanted to address the compiler errors.

score 0 · Answer 4 · answered Jan 15 '14 at 15:39

As far as I see there is whole bunch of problems with provided code.

In your first code sample you introduce function declaration and private fields within

public static void main(String[] args){ }

, so your class will not compile and hence you'll be unable to use it from some other class

Then, you are using variable before declaring it as @Tank suggested in his answer.

It's also considered to be a good practice to stick with generally accepted naming conventions and formatting.

How to convert money to change

4 Answers4

Linked