Trouble looping string with 99 bottles of beer - ruby

Question

I was able to count down to 97 bottle of beers but I am having trouble looping to count down to 1. Is it possible to create a loop with what I wrote? Here's what I have so far.
all_beers = (99).to_s
one_less = ((all_beers).to_i - 1).to_s
puts '' +
all_beers + ' bottles of beer on the wall, ' +
all_beers + ' bottles of beer. You take one down you pass it around ' +
one_less + ', beers on the wall!'
all_beers = one_less
one_less = ((all_beers).to_i - 1).to_s
puts '' +
all_beers + ' bottles of beer on the wall, ' +
all_beers + ' bottles of beer. You take one down you pass it around ' +
one_less + ', beers on the wall!'

Answer 1

use downto :
it will loop from the number you want upto the number you wish.
99.downto(1).each do |s|
all_beers = s
one_less = s - 1
puts '' +
all_beers.to_s + ' bottles of beer on the wall, ' +
all_beers.to_s + ' bottles of beer. You take one down you pass it around ' +
one_less.to_s + ', beers on the wall!'
end

Answer 2

Yes, it is certainly possible. This is taken from 99 Bottles of Beer project:
#
# Rubeer.rb
# by Eric Budd, Jan. 2008
#
# Demonstrates adding functionality to a built-in class, optional method parameters, inline
# conditionals, string replacement, alcohol aversion, and excessively fancy use of hashes.
#
# This borrows the hash from Daniel Straight's excellent implementation for the "wordalize" method
#
class Integer
NUMBER_WORDS = { 0 => "no", 1 => "one", 2 => "two", 3 => "three", 4 => "four", 5 => "five",
6 => "six", 7 => "seven", 8 => "eight", 9 => "nine",
10 => "ten", 11 => "eleven", 12 => "twelve", 13 => "thirteen",
14 => "fourteen", 15 => "fifteen", 16 => "sixteen", 17 => "seventeen",
18 => "eighteen", 19 => "nineteen",
20 => "twenty", 30 => "thirty", 40 => "forty", 50 => "fifty", 60 => "sixty",
70 => "seventy", 80 => "eighty", 90 => "ninety"}
def wordalize
raise "Invalid number to wordalize - should be in the range (0..99)" unless (0..99) === self
return NUMBER_WORDS[self] if self < 20
wordalized = NUMBER_WORDS[self - (self % 10)]
wordalized += '-' + NUMBER_WORDS[self % 10] unless (self % 10) == 0
return wordalized
end
def bottles
raise "Invalid number of bottles - should be in the range (0..99)" unless (0..99) === self
how_many_bottles = self.wordalize + ' bottle'
how_many_bottles += 's' unless self == 1
return how_many_bottles
end
alias :bottle :bottles # for grammar Nazis
end
def sing(number, teetotaller = false)
beverage = teetotaller ? 'coke' : 'beer'
puts "#{number.bottles.capitalize} of #{beverage} on the wall, #{number.bottles} of #{beverage}."
if number != 0
puts "Take one down, pass it around, #{(number - 1).bottles} of #{beverage} on the wall.\n\n"
else
puts "Go to the store and buy some more, 99 bottles of #{beverage} on the wall."
end
end
99.downto(0) { |number| sing(number) }
# Uncomment the following for the alternative teetotaller version
# 99.downto(0) { |number| sing(number, true) }
There are multiple Ruby versions uploaded there, but the default one is too complicated for beginners. This one, though, is very nice, and you should be able to understand what is going on.
The point that should answer your question is the bit with 99.downto(0) { |number| ... }. This is a loop that will repeat anything within the braces (in this case, sing(number)) a hundred times, with number going from 99 to 0.
Also note that it is inefficient (and illegible) to carry around the number as a string ((99).to_s) and convert it back to integer when you need it; rather, have it always be an integer, and convert it to string just before you need it as a string, when you display (or have the string concatenation/interpolation do it for you automatically, as in this piece of code).
While Ruby does have both for and while loops, they are rarely (while) or never (for) used. Instead, Rubyists usually rely on iterators and enumerators. Other functions like Integer#downto are Integer#upto, Integer#times and pretty much everything in the most awesome Enumerable mixin.

Answer 3

The short answer is yes, you can make a loop using what you wrote, and there are many ways of looping with ruby. However, since this seems to be about learning programming, considering that you did not use any control structures or string interpolation, not to mention casting that doesn't make much sense, I'd recommend Why's Poignant Guide to Ruby to learn the concepts of programming while using ruby.
As well as downto, you could do something like:
(1..99).reverse_each do |number|
bottle = number == 1 ? 'bottle' : 'bottles'
verse = "#{number} #{bottle} of beer on the wall, #{number} #{bottle} of beer. "
verse << "Take one down, pass it around, #{number-1} #{number-1 == 1 ? 'bottle' : 'bottles'} of beer on the wall"
puts verse
end

Answer 4

Things you may use to make your life easier: downto(), proc, ternary if (--that--thing--> ?:)
I enjoyed experiencing this exercise for the first time, so I'm a little hesitant about providing an answer here but so it goes.
It's a little bit more advanced, but using a 'proc' to make sure you pluralize "bottle(s)" correctly is a nice and clean way to get it done.
'downto()' is also an awesome way to iterate through those 99 bottles since it makes it feel like you're reading English instead of code.
num_at_start = 99 # You may change this number.
num_bottles = proc { |n| "#{n} bottle#{ n == 1 ? '' : 's'}" }
num_at_start.downto(1) do |num|
print "#{num_bottles.call(num)} of beer on the wall, " +
"#{num_bottles.call(num)} of beer!\n" +
"You take one down, pass it around, "
unless num == 1
puts "#{num_bottles.call(num - 1)} of beer on the wall!"
else
puts "No more bottles of beer on the wall!"
end
end
Source: Learn to Program 2nd Edition by Chris Pine (I changed a couple of things though)

Answer 5

This is the fix that I found for this question:
beer = 99
while beer > 0
puts beer.to_s + " bottles of beer on the wall. " + beer.to_s +
" bottles of beer."
(beer -= 1).to_s
puts "Take one down, pass it around. " + beer.to_s +
" bottles of beer on the wall."
end