how can I iterate through this array of hashes to receive a particular value : RUBY

Question

the hash I have is the following:

aoh=[
  { "name": "Vesper",
    "glass": "martini",
    "category": "Before Dinner Cocktail",
    "ingredients": [
      { "unit": "cl",
        "amount": 6,
        "ingredient": "Gin" },
      { "unit": "cl",
        "amount": 1.5,
        "ingredient": "Vodka" },
      { "unit": "cl",
        "amount": 0.75,
        "ingredient": "Lillet Blonde" }
    ],
    "garnish": "Lemon twist",
    "preparation": "Shake and strain into a chilled cocktail glass." },
  { "name": "Bacardi",
    "glass": "martini",
    "category": "Before Dinner Cocktail",
    "ingredients": [
      { "unit": "cl",
        "amount": 4.5,
        "ingredient": "White rum",
        "label": "Bacardi White Rum" },
      { "unit": "cl",
        "amount": 2,
        "ingredient": "Lime juice" },
      { "unit": "cl",
        "amount": 1,
        "ingredient": "Syrup",
        "label": "Grenadine" }
    ],
    "preparation": "Shake with ice cubes. Strain into chilled cocktail glass." }]

How can I iterate through this to get JUST the ingredient (without returning name,glass,category,etc.)? I also need the same iteration for amount but I assume that will look just like the iteration for ingredient. Sorry for the dumb question, I'm new to ruby and have attempted this for hours now.

Answer 1

You have an array of two elements in your example. Those two elements are hashes with key/value pairs. You can loop through the array with the #each method and access the values that the :"ingredients" keys store like this:

aoh.each do |hash|
  hash[:ingredients]
end

The :ingredients keys each store another array of hashes. An example hash is:

{ "unit": "cl",
        "amount": 6,
        "ingredient": "Gin" }

You can then access the value under the :ingredient key by doing hash[:ingredient]. The final result looks something like this:

   aoh.each do |array_element|
    array_element[:ingredients].each do |ingredient|
      ingredient[:ingredient]
    end
  end

This currently only iterates through the arrays and hashes. If you want to also print the result you can do this:

  aoh.each do |array_element|
    array_element[:ingredients].each do |ingredient|
      puts ingredient[:ingredient]
    end
  end
#=> Gin
#   Vodka
#   Lillet Blonde
#   White rum
#   Lime juice
#   Syrup

If you want to get a modified array, you can use #map (or #flat_map). You can also get the amount with the value like this:

   aoh.flat_map do |array_element|
    array_element[:ingredients].map do |ingredient|
      [[ingredient[:ingredient], ingredient[:amount]]
    end
  end
#=> [["Gin", 6], ["Vodka", 1.5], ["Lillet Blonde", 0.75], ["White rum", 4.5], ["Lime juice", 2], ["Syrup", 1]]

Answer 2

>aoh.collect { |i| i[:ingredients].collect { |g| puts g[:ingredient] } }
   Gin
   Vodka
   Lillet Blonde
   White rum
   Lime juice
   Syrup

Answer 3

I would suggest the following.

aoh=[
     { "name": "Vesper",
       "ingredients": [
         { "unit": "cl", "ingredient": "Gin" },
         { "unit": "cl", "ingredient": "Vodka" }
       ],
       "garnish": "Lemon twist"
     },
     { "name": "Bacardi",
       "ingredients": [
         { "unit": "cl", "ingredient": "White rum" },
         { "unit": "cl", "ingredient": "Lime juice" }
       ],
     }
   ]

aoh.each_with_object({}) { |g,h| h[g[:name]] =
  g[:ingredients].map { |f| f[:ingredient] } }
  #=> {"Vesper"=>["Gin", "Vodka"], "Bacardi"=>["White rum", "Lime juice"]}