For [Code Block, Proc, Lambda, and Closure in Ruby]()

construct3.rb

#Lambda
# 1. lambda followed by a code block
lambda { puts 'Hi' }
lambda do
  puts 'Hi'
end
#2. -> (stabby lambda)
-> { puts 'Hi' }
-> do
  puts 'Hi'
end
#-> takes argument outside of {}
times_2 = -> (num) { num * 2 }