Ruby Language Hashes Iterating Over a Hash
Example
A Hash includes the Enumerable module, which provides several iteration methods, such as: Enumerable#each, Enumerable#each_pair, Enumerable#each_key, and Enumerable#each_value.
.each and .each_pair iterate over each key-value pair:
h = { "first_name" => "John", "last_name" => "Doe" }
h.each do |key, value|
puts "#{key} = #{value}"
end
# => first_name = John
# last_name = Doe
.each_key iterates over the keys only:
h = { "first_name" => "John", "last_name" => "Doe" }
h.each_key do |key|
puts key
end
# => first_name
# last_name
.each_value iterates over the values only:
h = { "first_name" => "John", "last_name" => "Doe" }
h.each_value do |value|
puts value
end
# => John
# Doe
.each_with_index iterates over the elements and provides the index of the iteration:
h = { "first_name" => "John", "last_name" => "Doe" }
h.each_with_index do |(key, value), index|
puts "index: #{index} | key: #{key} | value: #{value}"
end
# => index: 0 | key: first_name | value: John
# index: 1 | key: last_name | value: Doe
