Ruby: nested hash iterations

How to iterate over nested hashes in ruby?

Before we can iterate through nested hashes, we must first know what a hash is.

hash: a hash is a collection of keys and values enclosed in curly brackets, hashes are identical to javascript objects.

nested hash ex:

 apple = {
 "Hardware Products" => {
   :computers => "Mac",
   :laptops => ["Macbook Pro", "Macbook Air"],
   :tablets => ["Ipad Air", "Ipad Pro"],
   :phones => "Iphone"
   },
   "Software Products" => {
    :entertainment => ["Apple Music", "Apple Tv", "Apple Podcast"],
    :finance => ["Apple Wallet", "Apple Card"],
    :other => ["Apple Fitness", "Apple Maps"]
   }
   }

nested hash of Apple's Hardware and Software products

The code block above is an example of a nested hash. A nested hash is normally a value pair in a hash.

Now that we are clear on what a hash is, how do we iterate over the nested hash?

example deliverable: output the :finance value["Apple Wallet", "Apple Card"]to the terminal.

step 1:
Iterate over the parent hash using each method, set two parameters to reference the key and value (product_type, inventory).

finance_products = apple.each do |product_type, inventory|
puts "product_type: #{product_type}"
puts "inventory: #{inventory}"
end

=> product_type => "Hardware Products"

=> inventory: => {
   computers => "Mac",
   laptops => ["Macbook Pro", "Macbook Air"],
   tablets => ["Ipad Air", "Ipad Pro"],
   phones => "Iphone"
   }

=> product_type => "Software Products"

=> inventory: => {
 :entertainment => ["Apple Music", "Apple Tv", "Apple Podcast"],
 :finance => ["Apple Wallet", "Apple Card"],
 :other => ["Apple Fitness", "Apple Maps"]
}

step 2:
Using a conditional statement (more on conditionals here) we access the value in "Software Products". Then iterate over value(inventory) and pass 2 parameters, these will reference the nested hash keys and values!

finance_products = apple.each do |product_type, inventory|

if product_type == "Software Products"

inventory.each do |product, type|
puts "product: #{product}"
puts "type: #{type}"
    end
   end
  end

"terminal output"

product: entertainment
type: ["Apple Music", "Apple Tv", "Apple Podcast"]
product: finance
type: ["Apple Wallet", "Apple Card"]
product: other
type: ["Apple Fitness", "Apple Maps"]

step 3:
Using a conditional statement to retrieve the :finance key from (product), we then iterate over the values(type) using each method and pass a parameter(finance) and print (finance) to meet the deliverable.

finance_products = apple.each do |product_type, inventory|

if product_type == "Software Products"

inventory.each do |product, type|

if product == :finance

type.each do |finance|
puts "#{finance}"

    end
   end
  end
 end 
end

"terminal output"

Apple Wallet
Apple Card