Simple FizzBuzz

Question

I wanted to try FizzBuzz, but to do it in the most efficient way. I think this method employs most of the concepts I learned here. Is there anything unaccounted for? A sprinkle of Swing since that's what I've been focusing on lately.

import javax.swing.JOptionPane;

    public class FizzBuzzCounter {
        public static void main(String[] args) {
            int goalNumber = Integer.parseInt(JOptionPane.showInputDialog("FizzBuzz goal number?"));
            fizzBuzzify(goalNumber);
        }
        public static void fizzBuzzify(int n) {
            for (int i = 1; i <= n; i++) {
                StringBuilder sb = new StringBuilder();
                if (i % 3 == 0) sb.append("Fizz");
                if (i % 5 == 0) sb.append("Buzz");
                if (sb.toString().isEmpty()) System.out.println(i);
                else System.out.println(sb.toString());
            }
        }
    }

Answer 1

There are a bunch of style issues you should be aware of, a validation problem, an optimization or two, and also an alternate approach:

Style:

Use braces for 1-liners... these are 'no-no' statements:

            if (i % 3 == 0) sb.append("Fizz");
            if (i % 5 == 0) sb.append("Buzz");
            if (sb.toString().isEmpty()) System.out.println(i);
            else System.out.println(sb.toString());

and should be:

          if (i % 3 == 0) {
              sb.append("Fizz");
          }
          if (i % 5 == 0) {
              sb.append("Buzz");
          }
          if (sb.toString().isEmpty()) {
              System.out.println(i);
          } else {
              System.out.println(sb.toString());
          }

Validation

Your OptionPanel blindly assumes the input will be a valid integer. This is not true, and you should build a validation sequence for it.

You should also catch 'NumberFormatException' from the Integer.parseInt(...)

Performance & alternate

The StringBuilder may make sense, but, if you use it, there are two things:

1. use sb.length() == 0 instead of sb.toString().isEmpty() which creates an unnecessary String value.
2. create the sb instance outside the loop, and reuse it, and sb.setLength(0) inside the loop to clear it.

But, in reality, there is no need for the StringBuilder if you use plain String Constants, and also use else-statements, and also use %15 (which is %3 and %5).

if (i % 15 == 0) {
    System.out.println("FizzBuzz");
} else if (i % 3 == 0) {
    System.out.println("Fizz");
} else if (i % 5 == 0) {
    System.out.println("Buzz");
} else {
    System.out.println(i);
}

Answer 2

import javax.swing.JOptionPane;

    public class FizzBuzzCounter {

Why is this way indented over here? I'm sure its a matter of copy/paste issues but the fact that you left it there wouldn't give me a good starting impression.

        public static void main(String[] args) {
            int goalNumber = Integer.parseInt(JOptionPane.showInputDialog("FizzBuzz goal number?"));

You've got bit of a strange mix here. Here you take input via a dialog, but you print to System.out below. That's a confused mix.

            fizzBuzzify(goalNumber);

What does it mean to fizzBuffiy something? It'd be better to call printFizzBuzz or something.

        }
        public static void fizzBuzzify(int n) {

The lack of a newline between functions sticks out to me. Of course, its not wrong, but pretty much every style has them.

            for (int i = 1; i <= n; i++) {
                StringBuilder sb = new StringBuilder();
                if (i % 3 == 0) sb.append("Fizz");
                if (i % 5 == 0) sb.append("Buzz");
                if (sb.toString().isEmpty()) System.out.println(i);
                else System.out.println(sb.toString());

This to me is the sign of a coder who has the mechanics of coding down, but doesn't have a good sense of readability. Its far harder to see what this code does in each case as compared to a more straightforward rendering such as that by @rolfl.

            }
        }
    }

Answer 3

A pet peeve of mine: Line length. A good style guide is to limit line length to 80 characters at most. This improves readability and makes code easier to understand.

This is even more important on stackexchange and github, where people also come to find good examples. Making them easier to read helps. (SE actually tends to break of code lines at different lengths, depending on the browser.)

This sample has a very long variable definition:

   public static void main(String[] args) {
        int goalNumber = Integer.parseInt(JOptionPane.showInputDialog("FizzBuzz goal number?"));
        fizzBuzzify(goalNumber);
    }

It can also be written as:

    public static void main(String[] args) {
        int goalNumber = Integer.parseInt(
            JOptionPane.showInputDialog("FizzBuzz goal number?")
        );
        fizzBuzzify(goalNumber);
    }

Doing a web search for 'Java style guide, line length' gives various resources: (Google actually highlighted the first one for me)

• CWU CS 110 Java Programming Style Guide (80)

• Android source Code Style (100)

(and many more, several of which can also be found in SO Resources for java coding style

Each language tends to have its own tradition, and in my experience, most vary between 72 and 132, with the median probably around 80.

Besides Java, we have Python's PEP8, with a general 80 character recommendation, but also A foolish consistency is the hobgoblin of little minds. Both are good advice.