ruby loops

loops.rb

# looping in ruby, from "The Ruby Way" by Hal Fulton
# added some rubymine stuff to get it cleanly inspected.

list = %w(alpha bravo charlie delta echo)

# 1 - while
i = 0
while i < list.size do
  print "#{list[i]} "
  i += 1
end
puts

# 2 - until
i = 0
until i == list.size do
  print "#{list[i]} "
  i += 1
end
puts

# 3 - post-test while / do while
i = 0
begin
  print "#{list[i]} "
  i += 1
end while i < list.size
puts

# 4 - post-test until / do until
i = 0
begin
  print "#{list[i]} "
  i += 1
end until i == list.size
puts

# 5 - for
# this one is bad form - rubymine complains!
# noinspection RubyForLoopInspection
for x in list do
  print "#{x} "
end
puts

# 6 - each iterator
list.each do |x|
  print "#{x} "
end
puts

# 7 - loop method
i = 0
n = list.size - 1
loop do
  print "#{list[i]} "
  i += 1
  break if i > n
end
puts

# 8 - loop method
i = 0
n = list.size - 1
loop do
  print "#{list[i]} "
  i += 1
  break unless i <= n
end
puts

# 9 - times iterator
n = list.size
n.times do |this_i|
  print "#{list[this_i]} "
end
puts

# 10 - upto iterator
n = list.size - 1
0.upto(n) do |this_i|
 print "#{list[this_i]} "
end
puts

# 11 - for with an iterator
n = list.size - 1
# rubymine complains that this is a dumb for loop.
# correct fix is to use a for.each, see 11.1
# noinspection RubyForLoopInspection
for this_i in 0..n do
  print "#{list[this_i]} "
end
puts

# 11.1 each - what rubymine want to change 11 into
(0..n).each {|this_i|
  print "#{list[this_i]} "
}
puts

# 12 - each_index iterator
list.each_index do |x|
  print "#{list[x]} "
end
puts