Working with yield in Ruby

block_exercises.rb

# Define a method named add_one that accepts
# a block and returns the return value of the
# block + 1, as follows.
# (Hint: yield gives you the return value of
# the block)
add_one do
  2
end
# => 3

# Define a method named change_number that
# accepts an integer and a block, and returns
# an integer as follows.
# (Hint: yield can receive arguments)
n = 1
change_number(n) do |x|
  x + 10
end
# => 11

# Define a method named change_array that
# accepts an array and a block, and returns
# an array as follows.
# (Hint: you can call yield multiple times)
a = [1, 2, 3]
change_array(a) do |x|
  x + 10
end
# => [11, 12, 13]

# Further reading: Look at how map works:
# (http://ruby-doc.org/core-2.2.0/Enumerable.html#method-i-map)
# It's the same as our change_array method!
# Blocks are really useful for working with
# arrays and hashes.