Say that I’m a… They help us to deal with situations in which a category or piece of data is associated not just to one discrete value, but to a collection of values. Ruby Hashes: Ruby Study Notes, You can subsequently retrieve the value by indexing the hash with the same key. Many simple applications won’t need a robust system for configuring the application and can go with a simple Ruby object, such as a hash, and a stored configuration file format such as YAML. However, while you index arrays with integers, you can index a hash with objects of any types: strings, regular expressions, and so on. Arrays, represented by square brackets, contain elements which are indexed beginning at 0. There is a method on hashes that. The key will be as you fix in the initial parameter, the second parameter will make a nested hash where the value will be an array you can push to with '<<'. Pinterest. Arrays and hashes are common data types used to store information. Read data from a nested array. # => false h = {s => 0} first_key = h. keys. The initial default value and initial default proc for the new hash depend on which form above was used. Ruby: create a Hash from Arrays Ruby has a very beatutiful expressiveness and offers a great standard library. value of the k key. But what do we do if we have a complex nested Hash with Arrays etc. When the single given argument is a Hash, returns a new Hash populated with the entries from the given Hash. items["milk"] = 5 items["eggs"] = 10 items["bread"] = 15 # Display the values. Ruby 2.3.0 introduced a new method called dig on both Hash and Array that solves this problem entirely.. value = structure.dig(:a, :b) It returns nil if the key is missing at any level.. access a key that doesn’t exist. You’ve probably heard that in Elixir you should let processes crash rather than trying to catch every possible exceptions. Let’s set up an example. Most of the time in Ruby we create our hashes by using the syntax we saw above. The names of the output files are computed by taking the name of the .proto file and making two changes: The extension (.proto) is replaced with _pb.rb. Ruby Hashes Hashes (sometimes known as associative arrays, maps, or dictionaries) are similar to arrays in that they are indexed collection of object references. Join the DZone community and get the full member experience. OpenStruct doesn't … setting its content, then this key will be created with a value missing ancestors will be created and the value will be associated to In Ruby you can create a Hash by assigning a key to a value with =>, separatethese key/value pairs with commas, and enclose the whole thing with curlybraces. A Hash is a collection of key-value pairs like this: "employee" = > "salary". The values in a hash can be objects of any type. frozen? When would you use a Hash? Copyright ©document.write(new Date().getFullYear()); All Rights Reserved, Connect econnrefused 127.0 0.1 node mysql, How to print last element of array in java, Public key is not available: NO_PUBKEY 78BD65473CB3BD13, C program to find the number of carry operations, Javascript get max value from array of objects. The main difference between an array and a hash is the manner in which data is stored. ancestors. Sometimes you’ll have to create a deeply nested hash without knowing how deep it can be at first. Tushar Shuvro posted Jul 19. s = 'foo' s. frozen? NoMethodError: undefined method `[]' for nil:NilClass, NoMethodError: undefined method `[]=' for nil:NilClass, GenServer with supervision tree and state recovery after crash. 3. Ruby hashes allow you to control how default values are created when a lookup occurs for a new key. Option create_additions (boolean) specifies whether to use JSON additions in parsing. It’s not something I need on a daily basis but it happens that I want ruby, But how do I read these nested values? Twitter. By using h[k] = h.dup.clear we Share Copy sharable link for this gist. Nested Hashes Intro, In this example, each key in our hash points to a value that is an array. Show solution. Summary. to be able to create a hash in which I could set or read the value for The Ruby script creates a names hash. If you read Hash.new documentation carefully you’ll notice that Nested hashes allow us to further group, or associate, the data we are working with. safe. This works exactly like the each method for an array object with one crucial difference. You can add elements in a particular hash with the help of another hash as well. which is our main hash, then clear its content and store it as the Try this method in irb by creating a hash like the one above, calling the method and passing keys like :one, :two, :four, and :ten. Returns a new Hash object populated with the given objects, if any. first first_key. We also use a hash. Digging through nested hashes Ruby provides a method Hash#dig which can be used in this case. A hash is useful to store what are called key/value pairs. Is this a solution to use in live code? Jordan Hudgens - January 20, 2017. the key. This is not a professional's tutorial. As you can see we can now assign a value to an arbitrarily deeply This hash should allow reading and setting values at any level without even having to manually create its ancestors if missing. This is exactly what we need to Thanks for the help, in advance. Nested Arrays, Hashes & Loops in Ruby, Arrays and hashes are common data types used to store information. an arbitrary deep key without even knowing if its ancestor keys Ruby Hashes - A Detailed Guide, Understand Ruby Hashes and common Ruby Hash methods. It is similar to an Array, except that indexing is done via arbitrary keys of any object type, not an integer index. All gists Back to GitHub Sign in Sign up Sign in Sign up {{ message }} Instantly share code, notes, and snippets. This cloning / clearing Like the array, these elements are placeholders that are used to pass each key/value pair into the code block as Ruby loops through the hash. That’s what happened with the hash["access"]["only"] call in our 5056. the hood it’s a call to the Hash.new method. puts items["milk"] puts items["eggs"] puts items["bread"] 5 10 15. The reason for this limitation is an ability to better adjust your app for … Skip to content. Ruby Hash to Object with OpenStruct and JSON zaiste.net, In Ruby you can Using custom to_json method in nested objects, I have a data structure that uses Returns a hash representing the model. A key-value store is the simplest concept of what a configuration object needs to be. Especially when you have to convert, merge or combine Arrays and Hashes. Ruby hash definition Ruby hash is a collection of key-value pairs. using this trick. It is similar to an array. A Hash assigns values to keys, so that values can be looked up by their key. To understand better what is multipart, you can see this question. kjakub / gist:be17d9439359d14e6f86. Arrays, represented by square brackets, contain elements which are indexed beginning at 0. Note that the index operator is used, but the student's name is used instead of a number.� values - Ruby: merge nested hash ruby merge multiple hashes (6) I would like to merge a nested hash. It is similar to an array. nested key in the hash without having to take care of creating call. 0. The answers/resolutions are collected from stackoverflow, are licensed under Creative Commons Attribution-ShareAlike license. are telling that if the key k is missing we want to duplicate h, If neither an argument nor a block given, initializes both the default value and the default proc to nil: Hashes, In Ruby you can create a Hash by assigning a key to a value with => , separate these key/value pairs with commas, and enclose the whole thing with curly braces. This is kind of recursion in a way. reusing our main hash behavior. In our example it’s going Raw. This coding exercise extends our knowledge on the Hash data structure and walks through how to check and see if a value exists in any number of Hash collections nested inside an array. As the name suggests, the method digs through the nested hash looking for keys we asked it to look for. ruby-on-rails ruby hash hash-of-hashes. The main difference between an array and a hash is the manner in which data is stored. Nested hashes allow us to further group, or associate, the data we are working with. Also called associative arrays, they are similar to Arrays, but where an Array uses integers as its index, a Hash allows you to use any object type.. Hashes enumerate their values in the order that the corresponding keys were inserted. Ruby is a very dynamic programming language. It is similar to an Array, except that indexing is done via arbitrary keys of any. a better way to do it since Ruby was designed with programmers We also refer to a value that is assigned to  A Hash is a similar Ruby data structure in that it allows you to work with a collection of items. A hash with three key/value pairs looks like this: { a: 1, b: 2, c: 3 } Where a is a key, and 1 is the corresponding value for that key. The well-cited RIP Hash rocket post would seem to imply the Hash Rocket syntax (:foo => "bar") is deprecated in favor of the new-to-Ruby JSON-style hash (foo: "bar"), but I can't find any definitive reference stating the Hash Rocket form is actually deprecated/unadvised as of Ruby 1.9. ruby-hash-rocket package. exists. hash = { person: { name: 'Rob', age: '28' } } hash.deep_transform_values{ |value| value.to_s.upcase } # => {person: {name: "ROB", age: "28"}} A hash can have a custom default value. Then, after a crash, you only have... Ruby is a very dynamic language which allows you to do things like encapsulate a piece of code in an object. Please note that I am a student and I started to learn Ruby in school few weeks ago. Embed. names2 = names1.dup We create a duplicate of the hash by calling the dupmethod. Let’s say I have a variable named hash that contains a hash: and I want to know what is the value for hash[:foo][:bar][:baz]: That was pretty predictable. The parameter to the --ruby_out= option is the directory where you want the compiler to write your Ruby output. defaulting to what was defined in the block. A hash variable can be created the same way as an array variable. However, a Hash is a dictionary of keys and values, where unlike an Array, the key can be of any object type. Ruby - Hashes, Ruby - Hashes - A Hash is a collection of key-value pairs like this: employee any Ruby object as a key or value, even an array, so the following example is a  Next Page A Hash is a collection of key-value pairs like this: "employee" = > "salary". Ruby, of course, also has dictionaries, but calls them “hashes.” In this posting, I’m going to show how we can create a hash in Ruby when iterating over an enumerable. You can also use new to create a hash with a default value, which is otherwise just nil − months = Hash.new ("month") or months = Hash.new "month" When you access any key in a hash that has a default value, if the key or value doesn't exist, accessing the hash will return the default value − Facebook . The main difference between an array and a hash is the manner in which data is stored. What would you like to do? Arrays have can only have integers. But if you try to read the value of a non-existing key, without What would you like to do? Assuming your data looks like this (I've  Nested Arrays, Hashes & Loops in Ruby June 9, 2014 by Koren Leslie Cohen Arrays and hashes are common data types used to store information. Instead of accessing keys in Hash, we want to access attributes (methods) on an object. This hash should allow reading and setting values at any level without even having to manually create its ancestors if missing. What is a Ruby hash? Let’s see how to do this. If it finds out any key which is not present, it just returns nil. Let’s see how to do this. Storing Values in a Ruby Hash. It’s time to create this deep hash by hand and it’s gonna be painful: I’m pretty sure you don’t like to write this kind of thing in your Tags: Adds a keymap for ctrl+l to insert " => " at the cursor position like Textmate used to. When I’m facing something like that I can’t stop thinking that there’s A slightly more complex way is an object-oriented approach that dyna… By. Nested Arrays, Hashes & Loops in Ruby. If the data doesn't have a natural label, then typically an array will work fine. Find that method by googling for “ruby hash key defined”. Create nested, or multidimensional, arrays. implement our infinitely deep nested hash! Embed. Ruby program that creates a hash # Create a new hash. Our world-class team is fluent in Ruby on Rails, Elixir, React, React Native, iOS, and Android, and we’re ready to design, build, and train so your product is rock-solid and user-friendly. As with arrays, there is a variety of ways to create hashes. source is a Ruby object. there is a signature that allows to pass a block to the Hash.new Now: Let’s look at how you can use hashes in your Ruby projects with common hash methods. A Hash can be easily created by using its implicit form: grades = { "Jane​  How do I create a Hash Table from this existing list with a different key (preserving the original list in separate variable name)? The order in which you traverse a hash by either key or value may seem arbitrary and will generally not be in the insertion order. This method is creating changes in the actual hash object because this method is one of the examples of destructive methods. [NEW REFCARD] Introduction to DevSecOps: Reach higher security standards while following DevOps principles ruby-on-rails,ruby,rack,multipart. 2. It is similar to an Array, except that indexing is done via arbitrary keys of any. A Hash can be easily created by using its implicit form: grades = { "Jane Doe" = > 10, "Jim Doe" = > 6 } Hashes allow an alternate syntax for keys that are symbols. Level Up Your Ruby Skillz: Working With Hashes, Hashes work pretty much like this. EDIT: More details. This is returned when a nonexistent key is accessed. This helps a lot when dealing with data structures. 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. Here is a quick However, a Hash is a dictionary of keys and values, where unlike an Array, the key can be of any object type. See ::new.. With no argument, returns a new empty Hash. This question is really more of a ruby question than a SketchUp API question but here goes anyways: I’ve created a hash of arrays: windows = {"window1"=> [84, 80], "window2"=> [84, 120], "window3"=>[48,80], etc...} The first value in the nested array is the location of the window along the length of the wall from the origin (left side). new_school=Hash.new(old_school) // ruby but I cant find out how to assign badge_ID field as new key for the hash. Default value. This is how it looks: This defines a Hash that contains 3 key/value pairs, meaning that we can lookup three values (the strings "eins", "zwei", and "drei") using threedifferent keys (the strings "one", "two", and "three"). tips, Categories: Working with Hashes in Ruby, A Hash is a similar Ruby data structure in that it allows you to work with a collection of items. module RubyDig def dig(key, *rest) if value = (self[key] rescue nil) if rest.empty? to be an empty hash. Returns a new hash with all values converted by the block operation. Ruby - Hashes - A Hash is a collection of key-value pairs like this: employee = > salary. Method 2: With the help of Hash.merge() method. Chef is a Ruby Gem which aims to help sys admins in the process of managing servers. Unlike arrays, there are no numerical indexes, you access the hash values with keys. It can seem a bit weird but actually it’s not. A Hash is a dictionary-like collection of unique keys and their values. black magic creates a new dynamic hash as the value for this key by 4. To go further, how do I assign a value to some deep key? The compiler creates a .rb file for each .proto file input. This hash should allow reading and setting values at any level without even having to manually create its ancestors if missing. Clone via HTTPS Clone with Git or checkout with SVN using the repository’s web address. The simplest method is to create an empty hash object and fill it with key/value pairs. This post was originally published at https://jessesbyers.github.io./ on January 23, 2020, when I was a Software Engineering student at Flatiron School.. This is a really powerful capability you can use... Knowing how to use the Rails console can be very useful when debugging or trying your snippets. As you have may notice there’s a gotcha you have to be aware of when items = Hash.new() # Store these key-value pairs in it. No, it’s not very readable however illustrates a system of forming data objects to fit your needs. methods on the object. How to Check if a Value Exists in a Set of Nested Hashes in Ruby. I have tried . By the way, the Ruby community has come up with the name hash rocket for thebit of syntax =>which separates a key from a value, … we think that … The example p040myhash. And Ruby’s Hashis the basic building block for all simple implementations of it — whether it’s a lone hash object or an object wrapping the hash with preferred behavior. Learn more about clone URLs Download ZIP. The order in which you traverse a hash by either key or value may seem arbitrary and will generally not be in the insertion order. This method is a public instance method that is defined in Ruby's library especially for Hash class. Notice that the key-value pairs are separated by commas. Generating JSON. happiness in mind. Like (0) Comment (0) Save. Write data to a nested array. Hashes, Understand Ruby Hashes and common Ruby Hash methods. So if you assign a value to a non-existing key, this key and all its That’s fine for common needs but you must know that this Creating a deeply nested Hash in Ruby - Bounga’s Home Sometimes you’ll have to create a deeply nested hash without knowing how deep it can be at first. See JSON Additions. You can create an empty hash with the new class method − months = Hash.new You can also use new to create a hash with a default value, which is otherwise just nil − months = Hash.new( "month" ) or months = Hash.new "month". Ruby hashes allow you to control how default values are created when a lookup occurs for a new key. 6.71K Views. Nested Hashes Intro, In this example, each key in our hash points to a value that is an array. A key/value pair has an identifier to signify which variable of the hash you want to access and a variable to store in that position in the hash. A hash is a data structure used to store data in the form of UNIQUE key-value pairs. syntax is only a syntactic sugar to quickly create a hash but under To be useable as a Hash key, objects must implement the methods hash and eql?.Note: this requirement does not apply if the Hash uses compare_by_id since comparison will then rely on the keys' object id instead of hash and eql?.. To generate a Ruby String containing JSON data, use method JSON.generate(source, opts), where. For example, a teacher might store a student's grades in a hash. Star 0 Fork 0; Star Code Revisions 7. I write code and I love doing it using Ruby, Elixir and Emacs. Creating Hashes. GitHub Gist: instantly share code, notes, and snippets. Iterate over a nested array. This includes the values from the root hash and from all nested hashes and arrays. The option include_root_in_json controls the top-level behavior of as_json.If true, as_json will emit a single root node named after the object’s type. That’s pretty awesome, isn’t it? This method works in a way that it carries out a comparison between two different hashes and returns a Boolean value. Ruby. Returns a new empty Hash object. Ruby hashes - learn Ruby hashes, Ruby hash definition​​ Ruby hash is a collection of key-value pairs. Tweet. block. Hash Tables Explained, As a quick refresher, this is what using a hash table looks like in Ruby: prices = { apple: 0.50 Create an array of size BUCKETS with all elements set to 0; table  Create a Hash With Key/Value Pairs . OpenStruct provides an easy way for us to do this: OpenStruct.new(hash). Some configuration can be passed through options.. How am I able to create a hash within a hash  Ruby - Hashes - A Hash is a collection of key-value pairs like this: employee = > salary. saw above. At Hashrocket, we have a passion for turning ideas into reality. Code Snippet. Hope that this little tip will help you someday. Nested Hash to Dotted Notation Hash in Ruby August 26, 2013 by RayCoder This was one practical problem I encountered in day-to-day coding in Ruby where I have nested Hash and I want to convert to a Dotted Notation Hash lets say for pretty printing or even print the Hash to csv! Creating a ruby nested hash with array as inner value. Hashes, In Ruby you can create a Hash by assigning a key to a value with => , separate these key/value In this example, dictionary is a Hash defined on the first line. It is similar to an Array, except that indexing is done via arbitrary keys of any object type, not an integer index. Most of the time in Ruby we create our hashes by using the syntax we In today’s tutorial we’ll look at how to use Hashes in Ruby. Unlike arrays, hashes can have arbitrary objects as indexes. Have fun and stay See Default Values.. Ruby Nested Hash each_pair. For a hash, you create two elements—one for the hash key and one for the value. Last active Apr 14, 2017. # => true User-Defined Hash Keys. So, a hash created as a default value when a lookup for an unseen key occurs will have the same default behavior. Being proficient with it will increase your productivity. Exercise 4.5. example. As soon as you’ll try to access a given key in the hash, it will Embed Embed this gist in your website. Store is the directory where you want the compiler to write your Ruby Skillz: working with Ruby create! Any type > salary ( 0 ) Save public instance method that is an array, except that indexing done! How you can use hashes in Ruby dictionary-like collection of key-value pairs are separated by commas better what is,... Implement it yourself: rescue nil ) if value = ( self [ key ] nil. Provides a method on hashes that allows to pass a block to the -- ruby_out= option the. Key which is not present, it just returns nil some deep key documentation for 2.0.0... M a… Creating a Ruby gem which aims to help sys admins in the process of managing.... System ruby create nested hash forming data objects to fit your needs to be an empty hash keymap for ctrl+l insert... A key that doesn’t exist ruby create nested hash Exists in a way that it carries out a comparison between two hashes. Of the time in Ruby, Elixir and Emacs hash definition Ruby hash methods tips, Categories: Study! That in Elixir you should let processes crash rather than trying to every. Root hash and from all nested hashes Ruby provides a method hash # dig which can be looked Up ruby create nested hash! With one crucial difference multipart, you can add elements in a particular hash with same! Use hashes in your Ruby output full member experience key/value pairs get the full member experience in. Hash key and one ruby create nested hash the hash Hash.merge ( ) # store key-value... Dig ( key, * rest ) if rest.empty what happened with the default... Use method JSON.generate ( source, opts ), where please note that I ’ m a… a... Simplest method is to create an empty hash object because this method works in a particular hash with values! It with key/value pairs array object with one crucial difference lookup occurs for a new hash depend on form... Our infinitely deep nested hash with arrays, represented by square brackets, contain elements which are indexed beginning 0. With arrays, represented by square brackets, contain elements which are indexed at! A student and I love doing it using Ruby, arrays and are... Values from the root hash and how to use hashes in your output. - a hash a.rb file for each.proto file input no argument, returns a boolean value works like. Working with ) on an object, how do I assign a value to some deep?! Objects, if any it’s going to be an empty hash at how you use... Hashes - a Detailed Guide, Understand Ruby hashes allow us to further group or! Gotcha you have to be an empty hash object populated with the entries from the root hash and from nested..., how do I assign a value to some deep ruby create nested hash hash.. I ’ m a… Creating a Ruby nested hash looking for keys we asked it look... The dupmethod that method by googling for “ruby hash key defined” hash and from all nested hashes Ruby a! Label, then typically an array with the same default behavior from arrays Ruby has a very beatutiful expressiveness offers... The new hash depend on which form above was used of managing servers n't … Ruby allow. How to use in live code value limits the amount of simultaneously files. Bread '' ] puts items [ `` milk '' ] 5 ruby create nested hash 15, it just returns nil if?. Hashes enumerate their values in a particular hash with the same default proc = (! I ’ m a… Creating a Ruby nested hash looking for keys we asked it to for... For keys we asked it to look for ) specifies whether to use live. That indexing is done via arbitrary keys of any object type, not an integer index an hash. In live code rather than trying to catch every possible exceptions time and within your budget with. Can add elements in a hash is a collection of key-value pairs was used key is accessed duplicate. Is a signature that allows to Check if ruby create nested hash certain key is defined on the.! Projects with common hash methods String containing JSON data, use method JSON.generate ( source opts... That allows to pass a block to the Hash.new call what are called key/value pairs ) // Ruby I. Values at any level without even having to manually create its ancestors if missing lookup for! Asked it to look for method that is defined in Ruby through nested hashes Intro, in this example a... Be used in this example, a teacher might store a student 's grades a. Than trying to catch every possible exceptions see::new.. with argument! The value by indexing the hash by calling the dupmethod are called key/value.! You to control how default values are created when a nonexistent key is defined the... Array as inner value by using the syntax we saw above control both input allowed and output formatting whether use... & Loops in Ruby, tips, Categories: Ruby, arrays and hashes are data... Associate, the data does n't have a natural label, then typically an array and a is... Input allowed and output formatting to some deep key clearing black magic creates a hash is simplest... Array variable in parsing few weeks ago we do if we have a label. Values at any level without even having to manually create its ancestors if missing are created when a for! Key for the hash should allow reading and setting values at any without! Is an array '' ] puts items [ `` bread '' ] items. This is returned when a lookup for an array, except that indexing is via! Keys and their values in a particular hash with array as inner.! Student and I love doing it using Ruby, arrays and hashes common. All nested hashes and arrays join the DZone community and get the full experience! Is this a solution to use in live code rescue nil ) if value (. That doesn’t exist JSON data, use method JSON.generate ( source, opts ), where 2.3. And returns a new empty hash object and fill it with key/value pairs Ruby. Is useful to store information or checkout with SVN using the syntax we above... Empty hash new hash populated with the help of Hash.merge ( ) # store these key-value pairs object this... Or checkout with SVN using the repository ’ s web address if data... Passion for turning ideas into reality few weeks ago in this example, each key our! Ruby gem which aims to help sys ruby create nested hash in the actual hash object and it. Where you want the compiler to write your Ruby output share code, notes, you can subsequently retrieve value! Guide, Understand Ruby hashes allow you to control how default values are created when a nonexistent is... By using the syntax we saw above at the cursor position like Textmate to! Ruby we create our hashes by using the syntax we saw above Fork 0 ; code... Hash with arrays etc # = > 0 } first_key = h. keys hash... Hash.Merge ( ) # store these key-value pairs in it and their values in a hash can created. Have the same default proc for the new hash it short, this value limits the of! Grades in a particular hash with all values converted by the block operation value limits ruby create nested hash of. We create our hashes by using the syntax we saw above a Detailed Guide, Understand Ruby hashes - Detailed! A Detailed Guide, Understand Ruby hashes - a Detailed Guide, Understand Ruby hashes and a. Openstruct does n't have a natural label, then typically an array and ruby create nested hash hash is collection! To use JSON additions in parsing it is similar to an array will work fine documentation carefully notice... Any object type, not an integer index use the ruby_dig gem or implement it yourself: ).! Objects of any type concept of what a configuration object needs to be aware ruby create nested hash when using this trick arrays. Allows to Check if a certain key is accessed dig which can be objects of any type a gem! Us to do this: `` employee '' = > `` at the position... Lookup for an array, except that indexing is done via arbitrary keys of any an array arrays and.. Turning ideas into reality Ruby Skillz: working with data, use method JSON.generate source... You may ask what’s the sorcery done in our example new block carefully you’ll notice that the corresponding were... Actually it’s not very readable however illustrates a system of forming data objects to fit your needs Study,! Arrays and hashes in the form of unique key-value pairs by googling for hash. Enumerate their values in a hash is a public instance method that is an,... Should let processes crash rather than trying to catch every possible exceptions input and. 0 ) Save deep nested hash looking for keys we asked it to for. Specifies whether to use JSON additions in parsing each method for an unseen key occurs will the. Names2 = names1.dup we create a new hash depend on which form above was used use the ruby_dig or! Associate, the data does n't have a complex nested hash looking for keys we asked to... Especially for hash class salary '' to access attributes ( methods ) on an object arrays. Are collected from stackoverflow, are licensed under Creative Commons Attribution-ShareAlike license Ruby containing! You access the hash by calling the dupmethod key for the value notes.