Head First Java - Beer question

[Narin Kittikul]

Hi, everyone. I'm just starting out using Java, and I'm having some trouble correcting the error in the book's Beer song exercise. I've seen topics related to the Beer song question before, but mine is more about why the solution works as it does.

So, the original code is this:

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"); }
}
}
}

The problem with the original is that the final lines read:

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

I spent a good deal of time trying to fix that problem, only to look it up and find that the simple moving of the

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

to under the

beerNum = beerNum - 1;

fixed the whole problem.

However, I can't figure out why it fixes it. Can anyone please explain that to me?

[Nitish Bangera]

public class BeerSong 
{ 
public static void main(String[] args) 
{ 
int beerNum = 99; 
String word = "bottles"; 
while (beerNum > 0) 
{ 
if (beerNum == 1)  // check is done here
{ 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.");//Assume beernum is 2 so if has already been check so word ="bottles" 
beerNum = beerNum - 1; //Now beernum = 1 but there is no mechanism to make word = "bottle"

if (beerNum > 0) //here
{ System.out.println(beerNum + " " + word + " of beer on the wall"); } 


else 
{ System.out.println("No more bottles of beer on the wall"); } 
} 
} 
}    

 
if (beerNum > 0) 
{
if(beerNum == 1) 
       word == "bottle";
System.out.println(beerNum + " " + word + " of beer on the wall"); } 

[Narin Kittikul]

Ah, I get it now. It took a while, I had to go line by line, but now I see how the process works. Thank you.

[Campbell Ritchie]

Nice to get a problem solved, isn't it?

And welcome to JavaRanch

[Narin Kittikul]

Thanks. Yeah, it's very satisfying to finally figure it out

[Campbell Ritchie]

And when you have understood such a problem, you will find it easier when a similar problem occurs in future.