FizzBuzz/Java

FizzBuzz/Java is part of FizzBuzz. You may find other members of FizzBuzz at Category:FizzBuzz.

If/else ladder

public class FizzBuzz{
	public static void main(String[] args){
		for(int i= 1; i <= 100; i++){
			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);
			}
		}
	}
}

Concatenation

public class FizzBuzz{
	public static void main(String[] args){
		for(int i= 1; i <= 100; i++){
			String output = "";
			if(i % 3 == 0) output += "Fizz";
			if(i % 5 == 0) output += "Buzz";
			if(output.equals("")) output += i;
			System.out.println(output);
		}
	}
}

Ternary operator

public class FizzBuzz{
	public static void main(String[] args){
		for(int i= 1; i <= 100; i++){
			System.out.println(i % 15 != 0 ? i % 5 != 0 ? i % 3 != 0 ? 
			i : "Fizz" : "Buzz" : "FizzBuzz");
		}
	}
}

Recursive

public String fizzBuzz(int n){
  String s = "";
  if (n == 0)
    return s;
  if((n % 5) == 0)
    s = "Buzz" + s;
  if((n % 3) == 0)
    s = "Fizz" + s;
  if (s.equals(""))
    s = n + "";   
  return fizzBuzz(n-1) + "\n" + s;
}

Alternative Recursive

public String fizzBuzz(int n){
  return (n>0) ? fizzBuzz(n-1) + 
    (n % 15 != 0? n % 5 != 0? n % 3 != 0? (n+"") :"Fizz" : "Buzz" : "FizzBuzz") 
               : "";
}

Using an array

class FizzBuzz {
  public static void main( String [] args ) {
    for( int i = 1 ; i <= 100 ; i++ ) {
      System.out.println( new String[]{ i+"", "Fizz", "Buzz", "FizzBuzz" }[ ( i%3==0?1:0 ) + ( i%5==0?2:0 ) ]);
    }
  }
}

Lambda with Arrays

class FizzBuzz {
  public static void main( String [] args ) {
    int [] x = new int [100];
    Arrays.setAll(x, j -> j);
    Arrays.stream(x).forEach(i -> {
        if(i == 0) return;
        String output = "";
        if(i % 3 == 0) output += "Fizz";
        if(i % 5 == 0) output += "Buzz";
        if(output.equals("")) output += i;
        System.out.println(output);
    });
  }
}

Lambda with Streams

package fizzbuzz;

import static java.util.stream.IntStream.rangeClosed;

public interface FizzBuzz {
  public static void main(String... arguments) {
    rangeClosed(1, 100)
      .mapToObj(i -> {
        if (i % (3 * 5) == 0) {
          return "FizzBuzz";
        } else if (i % 3 == 0) {
          return "Fizz";
        } else if (i % 5 == 0) {
          return "Buzz";
        } else {
          return Integer.toString(i);
        }
      })
      .forEach(System.out::println)
    ;
  }
}

OO style

public class FizzBuzz {

    public static void main(String[] args) {
        Sound sound = new Sound(3, "Fizz", new Sound(5, "Buzz"));
        for (int i = 1; i <= 100; i++) {
            System.out.println(sound.generate(i));
        }
    }

    private static class Sound {
        private final int trigger;
        private final String onomatopoeia;
        private final Sound next;

        public Sound(int trigger, String onomatopoeia, Sound next) {
            this.trigger = trigger;
            this.onomatopoeia = onomatopoeia;
            this.next = next;
        }

        public Sound(int trigger, String sound) {
            this(trigger, sound, null);
        }

        public String generate(int i) {
            StringBuilder sb = new StringBuilder();
            generate(sb, i);
            return sb.length() == 0 ? String.valueOf(i) : sb.toString();
        }
        
        private void generate(StringBuilder sb, int i) {
            if (i % trigger == 0)
                sb.append(onomatopoeia);
            if (next != null) 
                next.generate(sb, i);
        }

    }

}

Enum-based Declarative

With Functional and OO elements

A new rule can be added by adding a single line.

import java.util.Arrays;
import java.util.function.IntPredicate;
import java.util.stream.IntStream;

public enum FizzBuzz {
    Fizz(divisibleBy(3)),
    Buzz(divisibleBy(5));

    private final IntPredicate test;

    FizzBuzz(IntPredicate test) {
        this.test = test;
    }

    static IntPredicate divisibleBy(int i) {
        return n -> n % i == 0;
    }

    String applyRule(int n) {
        if (test.test(n))
            return name();
        return "";
    }

    static String print(int i) {
        String byRules = Arrays.stream(values())
                .map(rule -> rule.applyRule(i))
                .collect(Collectors.joining());
        if (byRules.isEmpty())
            return i + "";
        return byRules;
    }

    public static void main(String[] args) {
        IntStream.rangeClosed(1, 100)
                .mapToObj(FizzBuzz::print)
                .forEach(System.out::println);
    }
    
}