Head first Beersong

[Besjamain Greenaway]

Hello all,

just started with programming in Java, and now ended up at the beerSong. I try to figure out what is going wrong (since the output shows "99 bottles of beer on the wall" twice before going on to "99 bottles of beer"), but I am as blind as a mole about the "little flaw". Anyone could give me a hint as to where I should look?

Thanks!

[Campbell Ritchie]

Not familiar with that particular affliction; English kids sing, "Ten green bottles standing on the wall," and normally repeat the first line.

This sounds like a common kind of error called "out-by-one." Are you repeating the call? How are you repeating it? Show us what you have got, and tell us where you think the problem is. Then see if we can't help you.

CR

[Besjamain Greenaway]

Thanks for replying! Well, this is what I have;

  public class BeerSong {
    public static void main(String[] args) {
        int beerNum = 99;
        String word = "bottles";
        while (beerNum > 0)
        {
            if (beerNum == 1)
            {
                word = "bottle";
            }
            System.out.println(beerNum + " " + word + " of beer on the wall");
            System.out.println(beerNum + " " + word + " of beer");
            System.out.println("Take one down.");
            System.out.println("Pass it around.");
            beerNum = beerNum - 1;
            if (beerNum > 0)
            {
                System.out.println(beerNum +  " " + word + " of beer on the wall");
            }
            else
            {
                System.out.println("No more bottles of beer on the wall");
            }
        }
    }
}  

This is the code that's in the head first java book on page 14. There's a flaw in it, since it will output this:

2 bottles of beer on the wall
2 bottles of beer on the wall
2 bottles of beer
Take one down.
Pass it around.

While it should be:

2 bottles of beer on the wall
2 bottles of beer
Take one down.
Pass it around.
2 bottles of beer on the wall.

At least, that's what I'm thinking it should be (I'm Dutch)....

[Campbell Ritchie]

Thank you. I tried it and it printed

campbell@campbell-laptop:~/java$ java BeerSong
99 bottles of beer on the wall
99 bottles of beer
Take one down.
Pass it around.
98 bottles of beer on the wall
98 bottles of beer on the wall
98 bottles of beer
Take one down.
Pass it around.

Suggest you put a "System.out.println("************");" at the end of each verse/stanza, as the second line in the "if (beerNum > 0)" block. Then you will have ************ separating verses which makes it easier to read.
There is another minor error; I am getting "1 bottles of beer . . ." as the last line of the penultimate verse/stanza. Check whether you are changing "bottles" to "bottle" at the right place.

Try that.

Is the line printing "no more bottles of beer on the wall" in the right place? I don't think so.

************************************************************************

As they say on "Red Dwarf": ADDITIONAL.

Is that really the form Head First suggest you program? This does not count as object-oriented programming. You are not creating any objects. But it can easily be converted to object-oriented programming . . .

You ought not to have so much code in the main method. You should only have

{
   new BeerSong(99).sing();
}//end main

in it. Put a field

private int beerNum;

and set it up in the constructor. Then you can put the loop in the sing() method.

[Dick Summerfield]

I had a look at your code:

public class BeerSong
{
    public static void main(String[] args)
    {
        int beerNum = 99;
        String word = "bottles";
        while (beerNum > 0)
        {
            if (beerNum == 1)
            {
                word = "bottle";
            }
            System.out.println(beerNum + " " + word + " of beer on the wall");
            System.out.println(beerNum + " " + word + " of beer");
            System.out.println("Take one down.");
            System.out.println("Pass it around.");
            beerNum = beerNum - 1;
            if (beerNum > 0)
            {
                //System.out.println(beerNum +  " " + word + " of beer on the wall");
            }
            else
            {
                System.out.println("No more bottles of beer on the wall");
            }
        }
    }
}

and it appears that if you comment out the System.out.println shown, you get rid of the repeated line. I tried it with int beerNum = 3; to limit output. The repeated lines for 1 bottle gives you a clue - the first says "1 bottles" the second "1 bottle" indicating which System.out.println they come from.

The program could do with a bit of refactoring though after commenting out that line

Groetjes, Dick uit Eindhoven.

[Henry Wong]

and it appears that if you comment out the System.out.println shown, you get rid of the repeated line.

Yes, you'll get rid of the repeated line, but that's not how the song goes!! The song does repeat lines -- the end of a (number of bottle) verse is the start of the next verse.

Henry

[Campbell Ritchie]

Agree with Henry Wong that the line should be repeated as the first line of the next verse. That is why I suggested a ***************line to break it up. I am getting

campbell@campbell-laptop:~$ cd java
campbell@campbell-laptop:~/java$ java BeerSong
9 bottles of beer on the wall
9 bottles of beer
Take one down.
Pass it around.
8 bottles of beer on the wall
************
8 bottles of beer on the wall
8 bottles of beer
Take one down.
Pass it around.
7 bottles of beer on the wall
************
7 bottles of beer on the wall . . .

. . . using what I copied and pasted from Besjamain Greenaway's 2nd post, plus the ********** line.

In fact the looping could be tidied up quite a lot, but there are no major errors in it. What worries me is that you get books which don't introduce creating objects at an early stage.

[Bert Bates]

aw Campbell, you ought to have a little faith in us

[Besjamain Greenaway]

Wow, thanks for all the replies. Yes, this is not OO programming yet, they will get to that: I've just started out in the book

Okay - I understand now how the verse goes: after "pass it around, take one down" it should then go "xx of bottles on the wall", where xx is allready minus 1 from the one it started with.

Thanks for all your help, I got a better understanding of where to go now!

[Julia Adams]

this is my solution
i added if (beerNum == 0) condition instead of the if (beerNum > 0)

    
public class BeerSong {
	public static void main(String[] args) {  
		int beerNum = 99;  
        String word = "bottles";  
        while (beerNum > 0)  
        {  
            if (beerNum == 1)  
            {  
                word = "bottle";  
            }  
            System.out.println(beerNum + " " + word + " of beer on the wall");  
            System.out.println(beerNum + " " + word + " of beer");  
            System.out.println("Take one down.");  
            System.out.println("Pass it around.");  
            beerNum = beerNum - 1;  
            if (beerNum == 0)  
             
            {  
                System.out.println("No more bottles of beer on the wall");  
            }  
        }
}  
        }

[Campbell Ritchie]

Welcome to the Ranch Julia Adams

[David Patrzeba]

The flaw is that as you pass in 2 and take one down the program out puts:

1 bottles of beer on the wall

The solution is to rearrange the code so that the qualifier is after you remove the bottle.

[Sven Jansen]

So this is the right solution?

public class BeerSong {
	
	public static void main (String[] args) {
		int beerNum = 99;
		String word = "bottles";
		
		while (beerNum > 0) {
			
			System.out.print(beerNum + " " + word + " of beer on the wall, ");
			System.out.println(beerNum + " " + word + " of beer.");
			System.out.print("Take one down and pass it around, ");
			
			beerNum = beerNum - 1;
			
			if (beerNum == 1) {
				word = "bottle";
			}
			
			System.out.println(beerNum + " " + word + " of beer on the wall.");	
		}
		System.out.println("No more bottles of beer on the wall");
	}
			
}

cheers

[Campbell Ritchie]

Sven Brocking wrote:So this is the right solution? . . . cheers

Does it work?

Welcome to the Ranch

There is no such thing as "the" correct solution, but if that code works, it may be one of many correct solutions. We usually avoid giving a complete solution here, but your code differs so little from what was posted previously, I shall look on it as a correction of previous postings.

[Joel Christophel]

I know I'm a year late, but none of the programs posted yet were correct. However, David Patrzeba was correct with what he said. Based off of what he said, I moved the location of the qualifier, and the issue was removed. Here is a, not the, correct solution:

  public class BeerSong {  
    public static void main(String[] args) {  
        int beerNum = 99;  
        String word = "bottles";  
        while (beerNum > 0)  
        {  
            System.out.println(beerNum + " " + word + " of beer on the wall");  
            System.out.println(beerNum + " " + word + " of beer");  
            System.out.println("Take one down.");  
            System.out.println("Pass it around.");  
            beerNum = beerNum - 1;  
            
            if (beerNum == 1)  //Here is the qualifier, which I moved to fix the program.
            {  
                word = "bottle";  
            }  
           
            if (beerNum > 0)  
            {  
              System.out.println(beerNum +  " " + word + " of beer on the wall");  
            }  
            else  
            {  
                System.out.println("No more bottles of beer on the wall");  
            }  
        }  
    }  
}   

[jake dickens]

try removing 18-21 lines and see what happens then figure out why it made a double

[Glenn Delostrico]

Well, I just started myself and still no one go the answer right but one guy was very close. He forgot to add the comment block which was posted a while back so the code below should fix the problem.

  public class BeerSong {     
    public static void main(String[] args) {     
        int beerNum = 99;     
        String word = "bottles";     
        while (beerNum > 0)     
        {     
            System.out.println(beerNum + " " + word + " of beer on the wall");     
            System.out.println(beerNum + " " + word + " of beer");     
            System.out.println("Take one down.");     
            System.out.println("Pass it around.");     
            beerNum = beerNum - 1;     
               
            if (beerNum == 1)  //Here is the qualifier, which I moved to fix the program.   
            {     
                word = "bottle";     
            }     
              
            if (beerNum > 0)     
            {     
              System.out.println(beerNum +  " " + word + " of beer on the wall");
            }     
            else     
            {     
               // System.out.println("No more bottles of beer on the wall");[/color]     
            }     
        }     
    }     

[Campbell Ritchie]

Welcome to the Ranch

You have a test about whether beerNum > 0 inside a while (beerNum > 0) loop. It is much neater to move the "no more bottles" line outside the loop, then you don't need that test any more. You are duplicating a test with the change from "bottles" to "bottle", but that probably still fits better inside the loop.
By the way: your indentation is inconsistent. Sometimes you have { at the end of the line and sometimes on a line to itself. I prefer the line to itself convention, but that is a preference not a requirement. You should however be consistent about which convention you follow.

[Keith Engwall]

Campbell Ritchie wrote:Welcome to the Ranch

You have a test about whether beerNum > 0 inside a while (beerNum > 0) loop. It is much neater to move the "no more bottles" line outside the loop, then you don't need that test any more. You are duplicating a test with the change from "bottles" to "bottle", but that probably still fits better inside the loop.
By the way: your indentation is inconsistent. Sometimes you have { at the end of the line and sometimes on a line to itself. I prefer the line to itself convention, but that is a preference not a requirement. You should however be consistent about which convention you follow.

I tried what you suggested and I found that if you take out the test about whether beerNum > 0 , then it will print "0 bottle of beer on the wall" before it exits the while loop and prints "No more bottles of beer on the wall". That's not correct.

In my opinion, that if/else test is the most elegant way to represent the decision of what to print as the last line of each stanza... if it's any stanza but the last, print the number of bottles of beer left, but if it's the last stanza, print "No more bottles". Comments would help clarify the meaning, of course.

       if (beerNum > 0)  {  // if this is any stanza but the last one, print the following
         System.out.println(beerNum + " " + word + " of beer on the wall")    ;
       } else { // on the last stanza, print the following
         System.out.println("No more bottles of beer on the wall");
       }

There may be a more efficient way in terms of computer cycles to handle the situation, but sometimes I find it's better to invest those cycles in making the code make more sense to someone down the line (often my future self) who has to figure out what I was trying to do.

And as for the original problem with bottles vs. bottle when beerNum is reduced to 1, I agree that setting word to "bottle" after beerNum is reduced to 1 makes a great deal of sense.

Here's my "final" code... I added punctuation to the first line, dividers between stanzas, and draw out the last line the way we used to do on those long car trips.

public class BeerSong {
  public static void main (String[] args) {
     int beerNum = 99; // song starts with 99 bottles of beer
     String word = "bottles" ;  // most of the song uses the word "bottles"
                                       
     while (beerNum > 0) {  // keep singing until we're out of beer!
       // begin stanza
       System.out.println(beerNum + " " + word + " of beer on the wall,");
       System.out.println(beerNum + " " + word + " of beer.");
       System.out.println("Take one down.");
       System.out.println("Pass it around.");
       beerNum = beerNum - 1;
       if (beerNum == 1) {  // only one "bottle" left!
         word = "bottle";  // we may be drunk, but we can still use good grammar!
       }
       
       // last line... decision time!
       if (beerNum > 0)  {  // in every stanza but the last...
         // last line tells number of beers left
         System.out.println(beerNum + " " + word + " of beer on the wall.");
         System.out.println("------") ;  // divide each stanza for easier reading
       } else { // no more beer! :(    It's the last stanza, so...
         // last line is different
         System.out.println("Nooo mooore bottles of beeeer on the wallll!"); // with feeling!
       }
       // end stanza
     }
     // song's over... are we there yet?  I have to go to the bathroom!
  }
}

If you don't like my comments, blame the beer! ;-D

[Nolan Lefler]

I have just started with HF Java, and this is the code I wrote. It works for me.

public class BeerSong {
	public static void main(String[] args) {
		int beerNum = 99;
		String word = "bottles";

		while (beerNum > 0) {
		
			System.out.println(beerNum + " " + word + " of beer on the wall");
			System.out.println(beerNum + " " + word + " of beer.");
			System.out.println("Take one down.");
			System.out.println("Pass it around.");
			beerNum = beerNum - 1;

			if (beerNum == 1) {
				word = "bottle";
			}

			if (beerNum > 0) {
				System.out.println(beerNum + " " + word + " of beer on the wall");
			}
			else {
				System.out.println("No more bottles of beer on the wall");
			}
		}
	}
}

[Rebecca Herbert]

while the 99 bottles of beer is an exception, the rest of the song is correct.

99 bottles of beer on the wall
99 bottles of beer
take one down
pass it around
98 bottles of beer on the wall

98 bottles of beer on the wall

And so on.

[Campbell Ritchie]

Welcome to the Ranch

[harinath cool]

public class Onebeer {
public static void main(String[] args) {
int beerNum = 99;
String word = "bottles";
while (beerNum > 0)
{
if (beerNum == 1)
{
word = "bottle";
}
System.out.println(beerNum + " " + word + " of beer on the wall");
System.out.println(beerNum + " " + word + " of beer");
System.out.println("Take one down.");
System.out.println("Pass it around.");
beerNum = beerNum - 1;
}

if (beerNum > 0)
{
System.out.println(beerNum + " " + word + " of beer on the wall");
}
else
{
System.out.println("No more bottles of beer on the wall");


}
}
}

[harinath cool]

Just close the while loop before if loop start searching if beerNum>0 or not

[harinath cool]

3 bottles of beer on the wall
3 bottles of beer
Take one down.
Pass it around.
2 bottles of beer on the wall
2 bottles of beer
Take one down.
Pass it around.
1 bottle of beer on the wall
1 bottle of beer
Take one down.
Pass it around.
No more bottles of beer on the wall

[Campbell Ritchie]

Welcome to the Ranch

[Aftab Badsha]

Hi,

I know am late,but dived into HF few years back,then got lost midway n finally decided to check Java once again.

How about this?


public class BeerSong
{
public static void main (String[] args)
{
int beerNum = 5;
String phrase = "bottles";

while(beerNum>0)
{
System.out.println(beerNum + " " + phrase + " of beer on the wall ");
System.out.println(beerNum + " " + phrase + " of beer ");
System.out.println("Take one down");
System.out.println("Pass it around");

beerNum=beerNum-1;

if(beerNum>0)
{
if(beerNum==1)
{
phrase="bottle";
}
System.out.println(beerNum + " " + phrase + " of beer on the wall ");
}
else
{
System.out.println("No more bottles of beer on the wall");
}
}
}
}

[Campbell Ritchie]

Welcome to the Ranch
I hope it is not too late for an answer. I would have added code tags to your code, which would have improved it , but your code is not indented.

[Paulo Couto]

Here is my attempt to the same book exercise:

public class BeerSongFinal {
    public static void main(String[] args) {
        int beerNum = 99;
        String word = "bottles";

        while (beerNum > 0) {
            System.out.println(beerNum + " " + word + " of beer on the wall");
            System.out.println(beerNum + " " + word + " of beer.");
            System.out.println("Take on down.");
            System.out.println("Pass it around.");
            beerNum = beerNum - 1;

            if (beerNum == 1) {
                word = "bottle";
            }
            else if (beerNum == 0) {
                System.out.println("No more bottles of beer on the wall");
            }
        }
    }
}

[Joel Christophel]

Paulo Couto wrote:Here is my attempt to the same book exercise

Welcome to the ranch, Paulo Couto! Your example is very good, but you are missing one thing. Listen to the song here at this link http://youtu.be/Z7bmyjxJuVY?t=40s. Follow closely using the output of your program, and you should see your mistake within a matter of seconds.

[Paulo Couto]

Thanks for the welcome Joel.

So here is my second attempt after listen all those drunks:

public class BeerSongFinal {
    public static void main(String[] args) {
        int beerNum = 99;
        String word = "bottles";

        while (beerNum > 0) {
            System.out.println(beerNum + " " + word + " of beer on the wall");
            System.out.println(beerNum + " " + word + " of beer.");
            System.out.println("Take on down.");
            System.out.println("Pass it around.");
            beerNum = beerNum - 1;
            System.out.println(beerNum + " " + word + " of beer on the wall");

            if (beerNum == 1) {
                word = "bottle";
            }
            else if (beerNum == 0) {
                System.out.println("No more bottles of beer on the wall");
            }
        }
    }
}

Line 12 is what I added to the code.
I sure that the code isn't as elegant as it should be, but today is my first day learning Java. I don't have any programming experience so bear with me please.

[Joel Christophel]

Paulo Couto wrote:
today is my first day learning Java. I don't have any programming experience so bear with me please.

Quite impressive for the first day. Your change did fix up the problem I was talking about. There's also a pluralization issue when you get to one bottle of beer, and "0 bottle of beer on the wall" shouldn't be there. But that's quite nit-picky.

[Paulo Couto]

Thanks Joel. For now I 'm just following the 'Head First Java' book and hopefully I will learn something from it. With the amount of resources out there, finding the ones that fit your style it's kinda hard (if that makes any sense).

There's also a pluralization issue when you get to one bottle of beer, and "0 bottle of beer on the wall" shouldn't be there. But that's quite nit-picky.

I will try my best to solve this issue. Working and solving little code 'bugs' like this, it's a great way to also train my attention to details.

P.S - Sorry for my poor english.

[Joel Christophel]

Paulo Couto wrote:
P.S - Sorry for my poor english.

I wouldn't even have guessed that English isn't you first language.

[Paulo Couto]

Here is my final code:

public class BeerSongFinal {
    public static void main(String[] args) {
        int beerNum = 99;
        String word = "bottles";

        while (beerNum > 0) {
            System.out.println(beerNum + " " + word + " of beer on the wall");

            System.out.println(beerNum + " " + word + " of beer.");
            System.out.println("Take on down.");
            System.out.println("Pass it around.");
            beerNum = beerNum - 1;

        if (beerNum >= 2) {
            System.out.println(beerNum + " " + word + " of beer on the wall");
        }

        if (beerNum == 1) {
            word = "bottle";
            System.out.println(beerNum + " " + word + " of beer on the wall");
        }

        if (beerNum == 0) {
            System.out.println("No more bottles of beer on the wall");
        }
        }
    }
}

Pluralization issue and the "0 bottle of beer on the wall" output solved.
Even with all issues solved, code seems very repetitive. Lots of if's there and that doesn't seem right for me.
Any suggestions/critics are welcome.

[Campbell Ritchie]

Yes, you have some repeated code. I suggest you print that code out, correctly indented (the first if should be one place farther to the right, for example). Then get different coloured pens and mark the extent of the loop and each if. Then you can work out where to put the last three print statements so as to avoid the duplication. If you get them in the right location, you can reduce them to two. And they will look different from each other.
There is a good reason for several println statements at the beginning of that loop. Because println uses the platform‑specific line terminators, you get the correct line end every time you finish a println statement. Much better than messing around with \r and \n.

[Junilu Lacar]

When you see repetitive code, think "extract method refactoring" to eliminate duplication

[Max Grossenbacher]

This is how it worked for me, I get the repetition of and the word bottle is spelled correctly when there is only 1 (ONE) bottle:

public class BeerSong {
	public static void main(String[] args){
		int beerNum = 99;
		String word = "bottles";
		
		while (beerNum > 0) {

			
			System.out.println(beerNum + " " + word + " of beer on the wall");
			System.out.println(beerNum + " " + word + " of beer.");
			System.out.println("Take one down.");
			System.out.println("Pass it around.");
			beerNum = beerNum - 1;
			
			if (beerNum == 1) {
				word = "bottle"; //singular, as in ONE bottle
			}

			if (beerNum > 0) {
				System.out.println(beerNum + " " + word + " of beer on the wall");
			} else {
				System.out.println("No more bottles of beer on the wall");
			} // end else
		} // end while loop
	} // end main method
} // end class				

Hope this helps

[Campbell Ritchie]

Welcome to the Ranch
Why do you have the last if-else? You can get rid of that and still print no more bottles…

[Johan Fourie]

This is my attempt. I do not know the song at all.

public class BeerSong
{
    public static void main(String[] args) 
	{
	    int beerNum = 99;
		String word = "bottles";
		
		while (beerNum > 0) 
		{
			System.out.println(beerNum + " " + word + " of beer on the wall");
			System.out.println(beerNum + " " + word + " of beer.");
			System.out.println("Take one down.");
			System.out.println("Pass it around.");
			beerNum = beerNum - 1;
			
			if (beerNum == 1)
			{
			    word = "bottle"; // singular, as in ONE bottle.
			} // end if
			
			if (beerNum >= 1) 
			{
			    System.out.println(beerNum + " " + word + " of beer on the wall");
			} // end if
			
			System.out.println(); // break up song
		} // end while loop
		
		// Prints no matter what
		System.out.println("No more bottles of beer on the wall.");
	} // end main method
} // end class