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antonmry's solution

to Beer Song in the Java Track

Published at Oct 08 2019 · 1 comment
Instructions
Test suite
Solution

Recite the lyrics to that beloved classic, that field-trip favorite: 99 Bottles of Beer on the Wall.

Note that not all verses are identical.

99 bottles of beer on the wall, 99 bottles of beer.
Take one down and pass it around, 98 bottles of beer on the wall.

98 bottles of beer on the wall, 98 bottles of beer.
Take one down and pass it around, 97 bottles of beer on the wall.

97 bottles of beer on the wall, 97 bottles of beer.
Take one down and pass it around, 96 bottles of beer on the wall.

96 bottles of beer on the wall, 96 bottles of beer.
Take one down and pass it around, 95 bottles of beer on the wall.

95 bottles of beer on the wall, 95 bottles of beer.
Take one down and pass it around, 94 bottles of beer on the wall.

94 bottles of beer on the wall, 94 bottles of beer.
Take one down and pass it around, 93 bottles of beer on the wall.

93 bottles of beer on the wall, 93 bottles of beer.
Take one down and pass it around, 92 bottles of beer on the wall.

92 bottles of beer on the wall, 92 bottles of beer.
Take one down and pass it around, 91 bottles of beer on the wall.

91 bottles of beer on the wall, 91 bottles of beer.
Take one down and pass it around, 90 bottles of beer on the wall.

90 bottles of beer on the wall, 90 bottles of beer.
Take one down and pass it around, 89 bottles of beer on the wall.

89 bottles of beer on the wall, 89 bottles of beer.
Take one down and pass it around, 88 bottles of beer on the wall.

88 bottles of beer on the wall, 88 bottles of beer.
Take one down and pass it around, 87 bottles of beer on the wall.

87 bottles of beer on the wall, 87 bottles of beer.
Take one down and pass it around, 86 bottles of beer on the wall.

86 bottles of beer on the wall, 86 bottles of beer.
Take one down and pass it around, 85 bottles of beer on the wall.

85 bottles of beer on the wall, 85 bottles of beer.
Take one down and pass it around, 84 bottles of beer on the wall.

84 bottles of beer on the wall, 84 bottles of beer.
Take one down and pass it around, 83 bottles of beer on the wall.

83 bottles of beer on the wall, 83 bottles of beer.
Take one down and pass it around, 82 bottles of beer on the wall.

82 bottles of beer on the wall, 82 bottles of beer.
Take one down and pass it around, 81 bottles of beer on the wall.

81 bottles of beer on the wall, 81 bottles of beer.
Take one down and pass it around, 80 bottles of beer on the wall.

80 bottles of beer on the wall, 80 bottles of beer.
Take one down and pass it around, 79 bottles of beer on the wall.

79 bottles of beer on the wall, 79 bottles of beer.
Take one down and pass it around, 78 bottles of beer on the wall.

78 bottles of beer on the wall, 78 bottles of beer.
Take one down and pass it around, 77 bottles of beer on the wall.

77 bottles of beer on the wall, 77 bottles of beer.
Take one down and pass it around, 76 bottles of beer on the wall.

76 bottles of beer on the wall, 76 bottles of beer.
Take one down and pass it around, 75 bottles of beer on the wall.

75 bottles of beer on the wall, 75 bottles of beer.
Take one down and pass it around, 74 bottles of beer on the wall.

74 bottles of beer on the wall, 74 bottles of beer.
Take one down and pass it around, 73 bottles of beer on the wall.

73 bottles of beer on the wall, 73 bottles of beer.
Take one down and pass it around, 72 bottles of beer on the wall.

72 bottles of beer on the wall, 72 bottles of beer.
Take one down and pass it around, 71 bottles of beer on the wall.

71 bottles of beer on the wall, 71 bottles of beer.
Take one down and pass it around, 70 bottles of beer on the wall.

70 bottles of beer on the wall, 70 bottles of beer.
Take one down and pass it around, 69 bottles of beer on the wall.

69 bottles of beer on the wall, 69 bottles of beer.
Take one down and pass it around, 68 bottles of beer on the wall.

68 bottles of beer on the wall, 68 bottles of beer.
Take one down and pass it around, 67 bottles of beer on the wall.

67 bottles of beer on the wall, 67 bottles of beer.
Take one down and pass it around, 66 bottles of beer on the wall.

66 bottles of beer on the wall, 66 bottles of beer.
Take one down and pass it around, 65 bottles of beer on the wall.

65 bottles of beer on the wall, 65 bottles of beer.
Take one down and pass it around, 64 bottles of beer on the wall.

64 bottles of beer on the wall, 64 bottles of beer.
Take one down and pass it around, 63 bottles of beer on the wall.

63 bottles of beer on the wall, 63 bottles of beer.
Take one down and pass it around, 62 bottles of beer on the wall.

62 bottles of beer on the wall, 62 bottles of beer.
Take one down and pass it around, 61 bottles of beer on the wall.

61 bottles of beer on the wall, 61 bottles of beer.
Take one down and pass it around, 60 bottles of beer on the wall.

60 bottles of beer on the wall, 60 bottles of beer.
Take one down and pass it around, 59 bottles of beer on the wall.

59 bottles of beer on the wall, 59 bottles of beer.
Take one down and pass it around, 58 bottles of beer on the wall.

58 bottles of beer on the wall, 58 bottles of beer.
Take one down and pass it around, 57 bottles of beer on the wall.

57 bottles of beer on the wall, 57 bottles of beer.
Take one down and pass it around, 56 bottles of beer on the wall.

56 bottles of beer on the wall, 56 bottles of beer.
Take one down and pass it around, 55 bottles of beer on the wall.

55 bottles of beer on the wall, 55 bottles of beer.
Take one down and pass it around, 54 bottles of beer on the wall.

54 bottles of beer on the wall, 54 bottles of beer.
Take one down and pass it around, 53 bottles of beer on the wall.

53 bottles of beer on the wall, 53 bottles of beer.
Take one down and pass it around, 52 bottles of beer on the wall.

52 bottles of beer on the wall, 52 bottles of beer.
Take one down and pass it around, 51 bottles of beer on the wall.

51 bottles of beer on the wall, 51 bottles of beer.
Take one down and pass it around, 50 bottles of beer on the wall.

50 bottles of beer on the wall, 50 bottles of beer.
Take one down and pass it around, 49 bottles of beer on the wall.

49 bottles of beer on the wall, 49 bottles of beer.
Take one down and pass it around, 48 bottles of beer on the wall.

48 bottles of beer on the wall, 48 bottles of beer.
Take one down and pass it around, 47 bottles of beer on the wall.

47 bottles of beer on the wall, 47 bottles of beer.
Take one down and pass it around, 46 bottles of beer on the wall.

46 bottles of beer on the wall, 46 bottles of beer.
Take one down and pass it around, 45 bottles of beer on the wall.

45 bottles of beer on the wall, 45 bottles of beer.
Take one down and pass it around, 44 bottles of beer on the wall.

44 bottles of beer on the wall, 44 bottles of beer.
Take one down and pass it around, 43 bottles of beer on the wall.

43 bottles of beer on the wall, 43 bottles of beer.
Take one down and pass it around, 42 bottles of beer on the wall.

42 bottles of beer on the wall, 42 bottles of beer.
Take one down and pass it around, 41 bottles of beer on the wall.

41 bottles of beer on the wall, 41 bottles of beer.
Take one down and pass it around, 40 bottles of beer on the wall.

40 bottles of beer on the wall, 40 bottles of beer.
Take one down and pass it around, 39 bottles of beer on the wall.

39 bottles of beer on the wall, 39 bottles of beer.
Take one down and pass it around, 38 bottles of beer on the wall.

38 bottles of beer on the wall, 38 bottles of beer.
Take one down and pass it around, 37 bottles of beer on the wall.

37 bottles of beer on the wall, 37 bottles of beer.
Take one down and pass it around, 36 bottles of beer on the wall.

36 bottles of beer on the wall, 36 bottles of beer.
Take one down and pass it around, 35 bottles of beer on the wall.

35 bottles of beer on the wall, 35 bottles of beer.
Take one down and pass it around, 34 bottles of beer on the wall.

34 bottles of beer on the wall, 34 bottles of beer.
Take one down and pass it around, 33 bottles of beer on the wall.

33 bottles of beer on the wall, 33 bottles of beer.
Take one down and pass it around, 32 bottles of beer on the wall.

32 bottles of beer on the wall, 32 bottles of beer.
Take one down and pass it around, 31 bottles of beer on the wall.

31 bottles of beer on the wall, 31 bottles of beer.
Take one down and pass it around, 30 bottles of beer on the wall.

30 bottles of beer on the wall, 30 bottles of beer.
Take one down and pass it around, 29 bottles of beer on the wall.

29 bottles of beer on the wall, 29 bottles of beer.
Take one down and pass it around, 28 bottles of beer on the wall.

28 bottles of beer on the wall, 28 bottles of beer.
Take one down and pass it around, 27 bottles of beer on the wall.

27 bottles of beer on the wall, 27 bottles of beer.
Take one down and pass it around, 26 bottles of beer on the wall.

26 bottles of beer on the wall, 26 bottles of beer.
Take one down and pass it around, 25 bottles of beer on the wall.

25 bottles of beer on the wall, 25 bottles of beer.
Take one down and pass it around, 24 bottles of beer on the wall.

24 bottles of beer on the wall, 24 bottles of beer.
Take one down and pass it around, 23 bottles of beer on the wall.

23 bottles of beer on the wall, 23 bottles of beer.
Take one down and pass it around, 22 bottles of beer on the wall.

22 bottles of beer on the wall, 22 bottles of beer.
Take one down and pass it around, 21 bottles of beer on the wall.

21 bottles of beer on the wall, 21 bottles of beer.
Take one down and pass it around, 20 bottles of beer on the wall.

20 bottles of beer on the wall, 20 bottles of beer.
Take one down and pass it around, 19 bottles of beer on the wall.

19 bottles of beer on the wall, 19 bottles of beer.
Take one down and pass it around, 18 bottles of beer on the wall.

18 bottles of beer on the wall, 18 bottles of beer.
Take one down and pass it around, 17 bottles of beer on the wall.

17 bottles of beer on the wall, 17 bottles of beer.
Take one down and pass it around, 16 bottles of beer on the wall.

16 bottles of beer on the wall, 16 bottles of beer.
Take one down and pass it around, 15 bottles of beer on the wall.

15 bottles of beer on the wall, 15 bottles of beer.
Take one down and pass it around, 14 bottles of beer on the wall.

14 bottles of beer on the wall, 14 bottles of beer.
Take one down and pass it around, 13 bottles of beer on the wall.

13 bottles of beer on the wall, 13 bottles of beer.
Take one down and pass it around, 12 bottles of beer on the wall.

12 bottles of beer on the wall, 12 bottles of beer.
Take one down and pass it around, 11 bottles of beer on the wall.

11 bottles of beer on the wall, 11 bottles of beer.
Take one down and pass it around, 10 bottles of beer on the wall.

10 bottles of beer on the wall, 10 bottles of beer.
Take one down and pass it around, 9 bottles of beer on the wall.

9 bottles of beer on the wall, 9 bottles of beer.
Take one down and pass it around, 8 bottles of beer on the wall.

8 bottles of beer on the wall, 8 bottles of beer.
Take one down and pass it around, 7 bottles of beer on the wall.

7 bottles of beer on the wall, 7 bottles of beer.
Take one down and pass it around, 6 bottles of beer on the wall.

6 bottles of beer on the wall, 6 bottles of beer.
Take one down and pass it around, 5 bottles of beer on the wall.

5 bottles of beer on the wall, 5 bottles of beer.
Take one down and pass it around, 4 bottles of beer on the wall.

4 bottles of beer on the wall, 4 bottles of beer.
Take one down and pass it around, 3 bottles of beer on the wall.

3 bottles of beer on the wall, 3 bottles of beer.
Take one down and pass it around, 2 bottles of beer on the wall.

2 bottles of beer on the wall, 2 bottles of beer.
Take one down and pass it around, 1 bottle of beer on the wall.

1 bottle of beer on the wall, 1 bottle of beer.
Take it down and pass it around, no more bottles of beer on the wall.

No more bottles of beer on the wall, no more bottles of beer.
Go to the store and buy some more, 99 bottles of beer on the wall.

For bonus points

Did you get the tests passing and the code clean? If you want to, these are some additional things you could try:

  • Remove as much duplication as you possibly can.
  • Optimize for readability, even if it means introducing duplication.
  • If you've removed all the duplication, do you have a lot of conditionals? Try replacing the conditionals with polymorphism, if it applies in this language. How readable is it?

Then please share your thoughts in a comment on the submission. Did this experiment make the code better? Worse? Did you learn anything from it?

Setup

Go through the setup instructions for Java to install the necessary dependencies:

https://exercism.io/tracks/java/installation

Running the tests

You can run all the tests for an exercise by entering the following in your terminal:

$ gradle test

Use gradlew.bat if you're on Windows

In the test suites all tests but the first have been skipped.

Once you get a test passing, you can enable the next one by removing the @Ignore("Remove to run test") annotation.

Source

Learn to Program by Chris Pine http://pine.fm/LearnToProgram/?Chapter=06

Submitting Incomplete Solutions

It's possible to submit an incomplete solution so you can see how others have completed the exercise.

BeerSongTest.java

import org.junit.Test;
import org.junit.Ignore;
import org.junit.Before;

import static org.junit.Assert.assertEquals;

public class BeerSongTest {

    private BeerSong beerSong;

    @Before
    public void setup() {
        beerSong = new BeerSong();
    }

    @Test
    public void singFirstVerse() {
        assertEquals("99 bottles of beer on the wall, 99 bottles of beer.\n" +
                        "Take one down and pass it around, 98 bottles of beer on the wall.\n\n",
                beerSong.sing(99, 1));
    }

    @Ignore("Remove to run test")
    @Test
    public void singLastGenericVerse() {
        assertEquals("3 bottles of beer on the wall, 3 bottles of beer.\n" +
                        "Take one down and pass it around, 2 bottles of beer on the wall.\n\n",
                beerSong.sing(3, 1));
    }

    @Ignore("Remove to run test")
    @Test
    public void verseWithTwoBottles() {
        assertEquals("2 bottles of beer on the wall, 2 bottles of beer.\n" +
                        "Take one down and pass it around, 1 bottle of beer on the wall.\n\n",
                beerSong.sing(2, 1));
    }

    @Ignore("Remove to run test")
    @Test
    public void verseWithOneBottle() {
        assertEquals("1 bottle of beer on the wall, 1 bottle of beer.\n" +
                        "Take it down and pass it around, no more bottles of beer on the wall.\n\n",
                beerSong.sing(1, 1));
    }

    @Ignore("Remove to run test")
    @Test
    public void verseWithZeroBottles() {
        assertEquals("No more bottles of beer on the wall, no more bottles of beer.\n" +
                        "Go to the store and buy some more, 99 bottles of beer on the wall.\n\n",
                beerSong.sing(0, 1));
    }

    @Ignore("Remove to run test")
    @Test
    public void singFirstTwoVerses() {
        assertEquals("99 bottles of beer on the wall, 99 bottles of beer.\n" +
                        "Take one down and pass it around, 98 bottles of beer on the wall.\n\n" +
                        "98 bottles of beer on the wall, 98 bottles of beer.\n" +
                        "Take one down and pass it around, 97 bottles of beer on the wall.\n\n",
                beerSong.sing(99, 2));
    }

    @Ignore("Remove to run test")
    @Test
    public void singLastThreeVerses() {
        assertEquals("2 bottles of beer on the wall, 2 bottles of beer.\n" +
                        "Take one down and pass it around, 1 bottle of beer on the wall.\n\n" +
                        "1 bottle of beer on the wall, 1 bottle of beer.\n" +
                        "Take it down and pass it around, no more bottles of beer on the wall.\n\n" +
                        "No more bottles of beer on the wall, no more bottles of beer.\n" +
                        "Go to the store and buy some more, 99 bottles of beer on the wall.\n\n",
                beerSong.sing(2, 3));
    }

    @Ignore("Remove to run test")
    @Test
    public void singEntireSong() {
        assertEquals("99 bottles of beer on the wall, 99 bottles of beer.\nTake one down and pass it around, " +
                     "98 bottles of beer on the wall.\n\n" +
                     "98 bottles of beer on the wall, 98 bottles of beer.\nTake one down and pass it around, " +
                     "97 bottles of beer on the wall.\n\n" +
                     "97 bottles of beer on the wall, 97 bottles of beer.\nTake one down and pass it around, " +
                     "96 bottles of beer on the wall.\n\n" +
                     "96 bottles of beer on the wall, 96 bottles of beer.\nTake one down and pass it around, " +
                     "95 bottles of beer on the wall.\n\n" +
                     "95 bottles of beer on the wall, 95 bottles of beer.\nTake one down and pass it around, " +
                     "94 bottles of beer on the wall.\n\n" +
                     "94 bottles of beer on the wall, 94 bottles of beer.\nTake one down and pass it around, " +
                     "93 bottles of beer on the wall.\n\n" +
                     "93 bottles of beer on the wall, 93 bottles of beer.\nTake one down and pass it around, " +
                     "92 bottles of beer on the wall.\n\n" +
                     "92 bottles of beer on the wall, 92 bottles of beer.\nTake one down and pass it around, " +
                     "91 bottles of beer on the wall.\n\n" +
                     "91 bottles of beer on the wall, 91 bottles of beer.\nTake one down and pass it around, " +
                     "90 bottles of beer on the wall.\n\n" +
                     "90 bottles of beer on the wall, 90 bottles of beer.\nTake one down and pass it around, " +
                     "89 bottles of beer on the wall.\n\n" +
                     "89 bottles of beer on the wall, 89 bottles of beer.\nTake one down and pass it around, " +
                     "88 bottles of beer on the wall.\n\n" +
                     "88 bottles of beer on the wall, 88 bottles of beer.\nTake one down and pass it around, " +
                     "87 bottles of beer on the wall.\n\n" +
                     "87 bottles of beer on the wall, 87 bottles of beer.\nTake one down and pass it around, " +
                     "86 bottles of beer on the wall.\n\n" +
                     "86 bottles of beer on the wall, 86 bottles of beer.\nTake one down and pass it around, " +
                     "85 bottles of beer on the wall.\n\n" +
                     "85 bottles of beer on the wall, 85 bottles of beer.\nTake one down and pass it around, " +
                     "84 bottles of beer on the wall.\n\n" +
                     "84 bottles of beer on the wall, 84 bottles of beer.\nTake one down and pass it around, " +
                     "83 bottles of beer on the wall.\n\n" +
                     "83 bottles of beer on the wall, 83 bottles of beer.\nTake one down and pass it around, " +
                     "82 bottles of beer on the wall.\n\n" +
                     "82 bottles of beer on the wall, 82 bottles of beer.\nTake one down and pass it around, " +
                     "81 bottles of beer on the wall.\n\n" +
                     "81 bottles of beer on the wall, 81 bottles of beer.\nTake one down and pass it around, " +
                     "80 bottles of beer on the wall.\n\n" +
                     "80 bottles of beer on the wall, 80 bottles of beer.\nTake one down and pass it around, " +
                     "79 bottles of beer on the wall.\n\n" +
                     "79 bottles of beer on the wall, 79 bottles of beer.\nTake one down and pass it around, " +
                     "78 bottles of beer on the wall.\n\n" +
                     "78 bottles of beer on the wall, 78 bottles of beer.\nTake one down and pass it around, " +
                     "77 bottles of beer on the wall.\n\n" +
                     "77 bottles of beer on the wall, 77 bottles of beer.\nTake one down and pass it around, " +
                     "76 bottles of beer on the wall.\n\n" +
                     "76 bottles of beer on the wall, 76 bottles of beer.\nTake one down and pass it around, " +
                     "75 bottles of beer on the wall.\n\n" +
                     "75 bottles of beer on the wall, 75 bottles of beer.\nTake one down and pass it around, " +
                     "74 bottles of beer on the wall.\n\n" +
                     "74 bottles of beer on the wall, 74 bottles of beer.\nTake one down and pass it around, " +
                     "73 bottles of beer on the wall.\n\n" +
                     "73 bottles of beer on the wall, 73 bottles of beer.\nTake one down and pass it around, " +
                     "72 bottles of beer on the wall.\n\n" +
                     "72 bottles of beer on the wall, 72 bottles of beer.\nTake one down and pass it around, " +
                     "71 bottles of beer on the wall.\n\n" +
                     "71 bottles of beer on the wall, 71 bottles of beer.\nTake one down and pass it around, " +
                     "70 bottles of beer on the wall.\n\n" +
                     "70 bottles of beer on the wall, 70 bottles of beer.\nTake one down and pass it around, " +
                     "69 bottles of beer on the wall.\n\n" +
                     "69 bottles of beer on the wall, 69 bottles of beer.\nTake one down and pass it around, " +
                     "68 bottles of beer on the wall.\n\n" +
                     "68 bottles of beer on the wall, 68 bottles of beer.\nTake one down and pass it around, " +
                     "67 bottles of beer on the wall.\n\n" +
                     "67 bottles of beer on the wall, 67 bottles of beer.\nTake one down and pass it around, " +
                     "66 bottles of beer on the wall.\n\n" +
                     "66 bottles of beer on the wall, 66 bottles of beer.\nTake one down and pass it around, " +
                     "65 bottles of beer on the wall.\n\n" +
                     "65 bottles of beer on the wall, 65 bottles of beer.\nTake one down and pass it around, " +
                     "64 bottles of beer on the wall.\n\n" +
                     "64 bottles of beer on the wall, 64 bottles of beer.\nTake one down and pass it around, " +
                     "63 bottles of beer on the wall.\n\n" +
                     "63 bottles of beer on the wall, 63 bottles of beer.\nTake one down and pass it around, " +
                     "62 bottles of beer on the wall.\n\n" +
                     "62 bottles of beer on the wall, 62 bottles of beer.\nTake one down and pass it around, " +
                     "61 bottles of beer on the wall.\n\n" +
                     "61 bottles of beer on the wall, 61 bottles of beer.\nTake one down and pass it around, " +
                     "60 bottles of beer on the wall.\n\n" +
                     "60 bottles of beer on the wall, 60 bottles of beer.\nTake one down and pass it around, " +
                     "59 bottles of beer on the wall.\n\n" +
                     "59 bottles of beer on the wall, 59 bottles of beer.\nTake one down and pass it around, " +
                     "58 bottles of beer on the wall.\n\n" +
                     "58 bottles of beer on the wall, 58 bottles of beer.\nTake one down and pass it around, " +
                     "57 bottles of beer on the wall.\n\n" +
                     "57 bottles of beer on the wall, 57 bottles of beer.\nTake one down and pass it around, " +
                     "56 bottles of beer on the wall.\n\n" +
                     "56 bottles of beer on the wall, 56 bottles of beer.\nTake one down and pass it around, " +
                     "55 bottles of beer on the wall.\n\n" +
                     "55 bottles of beer on the wall, 55 bottles of beer.\nTake one down and pass it around, " +
                     "54 bottles of beer on the wall.\n\n" +
                     "54 bottles of beer on the wall, 54 bottles of beer.\nTake one down and pass it around, " +
                     "53 bottles of beer on the wall.\n\n" +
                     "53 bottles of beer on the wall, 53 bottles of beer.\nTake one down and pass it around, " +
                     "52 bottles of beer on the wall.\n\n" +
                     "52 bottles of beer on the wall, 52 bottles of beer.\nTake one down and pass it around, " +
                     "51 bottles of beer on the wall.\n\n" +
                     "51 bottles of beer on the wall, 51 bottles of beer.\nTake one down and pass it around, " +
                     "50 bottles of beer on the wall.\n\n" +
                     "50 bottles of beer on the wall, 50 bottles of beer.\nTake one down and pass it around, " +
                     "49 bottles of beer on the wall.\n\n" +
                     "49 bottles of beer on the wall, 49 bottles of beer.\nTake one down and pass it around, " +
                     "48 bottles of beer on the wall.\n\n" +
                     "48 bottles of beer on the wall, 48 bottles of beer.\nTake one down and pass it around, " +
                     "47 bottles of beer on the wall.\n\n" +
                     "47 bottles of beer on the wall, 47 bottles of beer.\nTake one down and pass it around, " +
                     "46 bottles of beer on the wall.\n\n" +
                     "46 bottles of beer on the wall, 46 bottles of beer.\nTake one down and pass it around, " +
                     "45 bottles of beer on the wall.\n\n" +
                     "45 bottles of beer on the wall, 45 bottles of beer.\nTake one down and pass it around, " +
                     "44 bottles of beer on the wall.\n\n" +
                     "44 bottles of beer on the wall, 44 bottles of beer.\nTake one down and pass it around, " +
                     "43 bottles of beer on the wall.\n\n" +
                     "43 bottles of beer on the wall, 43 bottles of beer.\nTake one down and pass it around, " +
                     "42 bottles of beer on the wall.\n\n" +
                     "42 bottles of beer on the wall, 42 bottles of beer.\nTake one down and pass it around, " +
                     "41 bottles of beer on the wall.\n\n" +
                     "41 bottles of beer on the wall, 41 bottles of beer.\nTake one down and pass it around, " +
                     "40 bottles of beer on the wall.\n\n" +
                     "40 bottles of beer on the wall, 40 bottles of beer.\nTake one down and pass it around, " +
                     "39 bottles of beer on the wall.\n\n" +
                     "39 bottles of beer on the wall, 39 bottles of beer.\nTake one down and pass it around, " +
                     "38 bottles of beer on the wall.\n\n" +
                     "38 bottles of beer on the wall, 38 bottles of beer.\nTake one down and pass it around, " +
                     "37 bottles of beer on the wall.\n\n" +
                     "37 bottles of beer on the wall, 37 bottles of beer.\nTake one down and pass it around, " +
                     "36 bottles of beer on the wall.\n\n" +
                     "36 bottles of beer on the wall, 36 bottles of beer.\nTake one down and pass it around, " +
                     "35 bottles of beer on the wall.\n\n" +
                     "35 bottles of beer on the wall, 35 bottles of beer.\nTake one down and pass it around, " +
                     "34 bottles of beer on the wall.\n\n" +
                     "34 bottles of beer on the wall, 34 bottles of beer.\nTake one down and pass it around, " +
                     "33 bottles of beer on the wall.\n\n" +
                     "33 bottles of beer on the wall, 33 bottles of beer.\nTake one down and pass it around, " +
                     "32 bottles of beer on the wall.\n\n" +
                     "32 bottles of beer on the wall, 32 bottles of beer.\nTake one down and pass it around, " +
                     "31 bottles of beer on the wall.\n\n" +
                     "31 bottles of beer on the wall, 31 bottles of beer.\nTake one down and pass it around, " +
                     "30 bottles of beer on the wall.\n\n" +
                     "30 bottles of beer on the wall, 30 bottles of beer.\nTake one down and pass it around, " +
                     "29 bottles of beer on the wall.\n\n" +
                     "29 bottles of beer on the wall, 29 bottles of beer.\nTake one down and pass it around, " +
                     "28 bottles of beer on the wall.\n\n" +
                     "28 bottles of beer on the wall, 28 bottles of beer.\nTake one down and pass it around, " +
                     "27 bottles of beer on the wall.\n\n" +
                     "27 bottles of beer on the wall, 27 bottles of beer.\nTake one down and pass it around, " +
                     "26 bottles of beer on the wall.\n\n" +
                     "26 bottles of beer on the wall, 26 bottles of beer.\nTake one down and pass it around, " +
                     "25 bottles of beer on the wall.\n\n" +
                     "25 bottles of beer on the wall, 25 bottles of beer.\nTake one down and pass it around, " +
                     "24 bottles of beer on the wall.\n\n" +
                     "24 bottles of beer on the wall, 24 bottles of beer.\nTake one down and pass it around, " +
                     "23 bottles of beer on the wall.\n\n" +
                     "23 bottles of beer on the wall, 23 bottles of beer.\nTake one down and pass it around, " +
                     "22 bottles of beer on the wall.\n\n" +
                     "22 bottles of beer on the wall, 22 bottles of beer.\nTake one down and pass it around, " +
                     "21 bottles of beer on the wall.\n\n" +
                     "21 bottles of beer on the wall, 21 bottles of beer.\nTake one down and pass it around, " +
                     "20 bottles of beer on the wall.\n\n" +
                     "20 bottles of beer on the wall, 20 bottles of beer.\nTake one down and pass it around, " +
                     "19 bottles of beer on the wall.\n\n" +
                     "19 bottles of beer on the wall, 19 bottles of beer.\nTake one down and pass it around, " +
                     "18 bottles of beer on the wall.\n\n" +
                     "18 bottles of beer on the wall, 18 bottles of beer.\nTake one down and pass it around, " +
                     "17 bottles of beer on the wall.\n\n" +
                     "17 bottles of beer on the wall, 17 bottles of beer.\nTake one down and pass it around, " +
                     "16 bottles of beer on the wall.\n\n" +
                     "16 bottles of beer on the wall, 16 bottles of beer.\nTake one down and pass it around, " +
                     "15 bottles of beer on the wall.\n\n" +
                     "15 bottles of beer on the wall, 15 bottles of beer.\nTake one down and pass it around, " +
                     "14 bottles of beer on the wall.\n\n" +
                     "14 bottles of beer on the wall, 14 bottles of beer.\nTake one down and pass it around, " +
                     "13 bottles of beer on the wall.\n\n" +
                     "13 bottles of beer on the wall, 13 bottles of beer.\nTake one down and pass it around, " +
                     "12 bottles of beer on the wall.\n\n" +
                     "12 bottles of beer on the wall, 12 bottles of beer.\nTake one down and pass it around, " +
                     "11 bottles of beer on the wall.\n\n" +
                     "11 bottles of beer on the wall, 11 bottles of beer.\nTake one down and pass it around, " +
                     "10 bottles of beer on the wall.\n\n" +
                     "10 bottles of beer on the wall, 10 bottles of beer.\nTake one down and pass it around, " +
                     "9 bottles of beer on the wall.\n\n" +
                     "9 bottles of beer on the wall, 9 bottles of beer.\nTake one down and pass it around, " +
                     "8 bottles of beer on the wall.\n\n" +
                     "8 bottles of beer on the wall, 8 bottles of beer.\nTake one down and pass it around, " +
                     "7 bottles of beer on the wall.\n\n" +
                     "7 bottles of beer on the wall, 7 bottles of beer.\nTake one down and pass it around, " +
                     "6 bottles of beer on the wall.\n\n" +
                     "6 bottles of beer on the wall, 6 bottles of beer.\nTake one down and pass it around, " +
                     "5 bottles of beer on the wall.\n\n" +
                     "5 bottles of beer on the wall, 5 bottles of beer.\nTake one down and pass it around, " +
                     "4 bottles of beer on the wall.\n\n" +
                     "4 bottles of beer on the wall, 4 bottles of beer.\nTake one down and pass it around, " +
                     "3 bottles of beer on the wall.\n\n" +
                     "3 bottles of beer on the wall, 3 bottles of beer.\nTake one down and pass it around, " +
                     "2 bottles of beer on the wall.\n\n" +
                     "2 bottles of beer on the wall, 2 bottles of beer.\nTake one down and pass it around, " +
                     "1 bottle of beer on the wall.\n\n" +
                     "1 bottle of beer on the wall, 1 bottle of beer.\nTake it down and pass it around, " +
                     "no more bottles of beer on the wall.\n\n" +
                     "No more bottles of beer on the wall, no more bottles of beer.\nGo to the store and buy " +
                     "some more, 99 bottles of beer on the wall.\n\n",
                beerSong.singSong());
    }

}
public class BeerSong {

    private final static String PHRASE_1 = "%d bottle%s of beer on the wall, %d bottle%s of beer."
            + System.getProperty("line.separator");
    private final static String PHRASE_2 = "Take %s down and pass it around, %d bottle%s of beer on the wall."
            + System.getProperty("line.separator") + System.getProperty("line.separator");
    private final static String PHRASE_ONE_BOTTLE = "Take it down and pass it around, no more bottles of beer on the wall."
            + System.getProperty("line.separator") + System.getProperty("line.separator");
    private final static String PHRASE_ZERO_BOTTLE_1 = "No more bottles of beer on the wall, no more bottles of beer."
            + System.getProperty("line.separator");
    private final static String PHRASE_ZERO_BOTTLE_2 = "Go to the store and buy some more, 99 bottles of beer on the wall."
            + System.getProperty("line.separator") + System.getProperty("line.separator");

    public String sing(int bottles, int verses) {
        StringBuilder sb = new StringBuilder();

        // This is a signal to end recursion
        if (verses == 0) {
            return "";
        }

        if (bottles == 0) {
            // Last two sentences of the song aren't reusable
            return sb.append(PHRASE_ZERO_BOTTLE_1).append(PHRASE_ZERO_BOTTLE_2).toString();
        }

        // Note: after this, we'll invoke again sing method in the return statements: recursion to build the song

        if (bottles == 1) {
            // Take care of singular and no more bottles
            sb.append(String.format(PHRASE_1, bottles, "", bottles, ""));
            return sb.append(PHRASE_ONE_BOTTLE).append(sing(bottles - 1, verses - 1)).toString();
        }

        sb.append(String.format(PHRASE_1, bottles, "s", bottles, "s"));

        if (bottles == 2) {
            // Take care of singular in the second phrase
            return sb.append(String.format(PHRASE_2, "one", bottles - 1, ""))
                    .append(sing(bottles - 1, verses - 1)).toString();
        }

        return sb.append(String.format(PHRASE_2, "one", bottles - 1, "s"))
                .append(sing(bottles - 1, verses - 1)).toString();

    }

    public String singSong() {
        return sing(99, 100);
    }
}

Community comments

Find this solution interesting? Ask the author a question to learn more.
Avatar of antonmry

This solution is quite complex compared with a simple for to build the song. Recursion is almost always a bad idea but I thought it would be fun to do it in that way.

antonmry's Reflection

Simple solution using recursion. Probably it isn't the most efficient solution even if the number is quite low.