cheat.sheets/sheets/_ruby/control_flow

# Basic iteration

# Good ol' for-loop
for i in [1, 2, 3]
  puts i
end

# Typically we don't use for-loops in Ruby, though.
# Rubyists tend to prefer .each
[1, 2, 3].each { |i| puts i }

# Using .each looks neater and it allows for powerful chaining
# of enumerable types.

# This example maps the array to [2, 4, 6] and prints each element.
[1, 2, 3].map { |i| i * 2 }.each { |i| puts i }

# Another kind of loop with specified iterations
10.times { puts 'test' }
10.times do |n|
  puts "number #{n}"
end

# Conditionals

if 2 * 4 == 8
  puts 'thank goodness'
else
  puts 'error between keyboard and chair'
end

# Add an extra condition
if 1 == 0
  puts 'oh no'
elsif 1 == 1
  puts "that's better"
else
  puts 'cut it out'
end

# unless means 'if not'
unless 1 == 0
  puts 'everything is ok'
end

# If the condition is short you can put it on one line.
happiness = 0 if 'my life'.empty?

# Or use ternary operator
happiness = 'my life'.empty? ? 0 : 100