Understanding recursion in the beer bottle example

Question

I am practicing recursion in C on my own and I found this example online. However there is one thing I don\'t understand.

void singSongFor(int numberOfBottle         


        

Answer 1

Note that the last printf uses the numberOfBottles variable, and that is never modified. So upon returning from printing oneFewer bottles, it will print the recycling text with numberOfBottles. Remember that there is one different incarnation of the local variables per each call to the function.

It can be seen easier if you indent the calls to the functions:

4 bottles of beer on the wall...
  3 bottles of beer on the wall...
    2 bottles of beer on the wall...
      1 bottles of beer on the wall...
        There are simply no more bottles of beer on the wall.
      Put a bottle in the recycling, 1 empty bottles in the bin.
    Put a bottle in the recycling, 2 empty bottles in the bin.
  Put a bottle in the recycling, 3 empty bottles in the bin.
Put a bottle in the recycling, 4 empty bottles in the bin.

Now, each line that begins in the same column is written from the same call of the function. Do you see how the number of bottles and recycling coindice? That's because both use the same variable: numberOfBottles.