Ruby Conditionals and Loops

if condition # check condition
  # code if true
elsif condition2 # additional check
  # code
else # default case
  # code
end # end if block

unless condition # if NOT condition
  # code executes when false
end
puts "Text" unless condition # inline unless

case variable # evaluate variable
when 1 # if variable is 1
  # code
when 2, 3 # if 2 or 3
  # code
else # default case
  # code
end

while condition # repeat while true
  # code
end
until condition # repeat until true
  # code
end

for i in 0..5 # loop 0 to 5
  puts i
end
array.each do |item| # iterate array
  puts item
end
5.times { puts "Hello" } # repeat 5 times

break # exit loop
next # skip to next iteration
redo # restart current iteration