Manipulating Output from an Array of Nested Hashes in Ruby

Ruby provides a couple of tools to help us comprehend arrays, hashes, and nested mixtures of both.

Assuming your data looks like this (I've added quotes around GOOG and FB):

data = [
  {"id"=>"1", "properties"=>{"name"=>"Google", "stock_symbol"=>"GOOG", "primary_role"=>"company"}},
  {"id"=>"2", "properties"=>{"name"=>"Facebook", "stock_symbol"=>"FB", "primary_role"=>"company"}}
]

You can iterate over the array using each, e.g.:

data.each do |result|
   puts result["id"]
end

Digging into a hash and printing the result can be done in a couple of ways:

data.each do |result|
  # method 1
  puts result["properties"]["name"]

  # method 2  
  puts result.dig("properties", "name")
end

Method #1 uses the hash[key] syntax, and because the first hash value is another hash, it can be chained to get the result you're after. The drawback of this approach is that if you have a missing properties key on one of your results, you'll get an error.

Method #2 uses dig, which accepts the nested keys as arguments (in order). It'll dig down into the nested hashes and pull out the value, but if any step is missing, it will return nil which can be a bit safer if you're handling data from an external source

Removing elements from a hash

Your second question is a little more involved. You've got two options:

1. Remove the primary_role keys from the nested hashes, or
2. Create a new object which contains all the data except the primary_role keys.

I'd generally go for the latter, and recommend reading up on immutability and immutable data structures.

However, to achieve [1] you can do an in-place delete of the key:

data.each do |company| 
  company["properties"].delete("primary_role")
end

Adding elements to a hash

You assign new hash values simply with hash[key] = value, so you can set the industry with something like:

data.each do |company| 
  company["properties"]["industry"] = "Advertising/Privacy Invasion"
end

which would leave you with something like:

[
  {
    "id"=>"1", 
    "properties"=>{
      "name"=>"Google", 
      "stock_symbol"=>"GOOG", 
      "industry"=>"Advertising/Privacy Invasion"
    }
  },
  {
    "id"=>"2", 
    "properties"=>{
      "name"=>"Facebook", 
      "stock_symbol"=>"FB", 
      "industry"=>"Advertising/Privacy Invasion"
    }
  }
]

To achieve the first operation, you can iterate through the array of companies and access the relevant information for each company. Here's an example in Ruby:

companies = [  {"id"=>"1", "properties"=>{"name"=>"Google", "stock_symbol"=>"GOOG", "primary_role"=>"company"}},  {"id"=>"2", "properties"=>{"name"=>"Facebook", "stock_symbol"=>"FB", "primary_role"=>"company"}}]

companies.each do |company|
  name = company['properties']['name']
  id = company['id']
  stock_symbol = company['properties']['stock_symbol']
  puts "#{name} - #{id} - #{stock_symbol}"
end

This will print out the name, ID, and stock symbol for each company.

To remove the "primary role" key/value, you can use the delete method on the properties hash. For example:

companies.each do |company|
  company['properties'].delete('primary_role')
end

To add a new "industry" key/value, you can use the []= operator to add a new key/value pair to the properties hash. For example:

companies.each do |company|
  company['properties']['industry'] = 'Technology'
end

This will add a new key/value pair with the key "industry" and the value "Technology" to the properties hash for each company.

this is the shortest way to achieve all those

companies = [
  {"id"=>"1", "properties"=>{"name"=>"Google", "stock_symbol"=>GOOG, "primary_role"=>"company"}},
  {"id"=>"2", "properties"=>{"name"=>"Facebook", "stock_symbol"=>FB, "primary_role"=>"company"}}
]

companies.each do |company| 
  puts "#{company["properties"]["name"]} - #{company["id"]} - #{company["properties"]["stock_symbol"]} "
  company["properties"].delete("primary_role")
  company[industry] 
end

data = [
  {"id"=>"1", "properties"=>{"name"=>"Google", "stock_symbol"=>"GOOG", "primary_role"=>"company"}},
  {"id"=>"2", "properties"=>{"name"=>"Facebook", "stock_symbol"=>"FB", "primary_role"=>"company"}}
]

data.each do |i|
  puts "This is id: #{i.dig("id")}"
  
  # Safely accessing and modifying nested properties
  i.dig("properties")&.delete("primary_role")  # Using dig to safely access "primary_role"
  i.dig("properties")&.store("industry", i.dig("properties", "name"))  # Using dig to access "name" and add "industry"
end

puts data

    Output:

This is id: 1
This is id: 2
{"id"=>"1", "properties"=>{"name"=>"Google", "stock_symbol"=>"GOOG", "industry"=>"Google"}}
{"id"=>"2", "properties"=>{"name"=>"Facebook", "stock_symbol"=>"FB", "industry"=>"Facebook"}}