Ruby hash get key value pair. Improve this question.

Ruby hash get key value pair Now: Let’s look at how you can I want to convert the hash's key/value pairs to only be values. Follow edited Jul 6, 2011 at 16:16. values] end keys, values = keysAndValues({a: 1, b: 2, c: 3}) keys # => [:a, :b, :c] values # => [1, 2, 3] Please note that Get key value pair of hash for the given key , in ruby. 4. This way you can also get smallest etc. Each element of the array will be the key, and I want to make the value being computed from that key. How to get the index of a key in a hash? 1. keys = @hash. [email protected]: I cant seem to figure this out, if i have a hash value can i then get the key thats associated to that value. I have a query that returns Array to hash of key value pairs in ruby. hash_one = Hash[array_one. to_h: Returns self if a Hash; if a subclass of Hash, returns a Hash containing the entries Let's say you just want an array of the keys or you just want an array of the values from a hash. To get the key, first needs to be called. keys it returns an array of the keys:. keys. sort_by {|k, v| v} test[0] end end I had to do something similar for a class I am taking. How to get min key value pair in hash. Example some_hash = {"name" => "tom", "uid"="100", Using Enumerable#max_by You can do the following: Iterate over the key-value pairs of the hash map using Enumerable#max_by ; Specify the value in the block to identify How to change a key-value pair of a hash in Ruby? Ask Question Asked 3 years, 2 months ago. However, all the keys that I actually care about are all unique. How to create a key value pair from the following data using ruby? result="-e hostname=webserver001 -e username=root -e password=testing123" I want to parse it and If I know there is only one key/value pair in a hash, is there a direct way to retrieve either the key or the value directly without having to get all the keys or values? here is a simple How can I get this into a key-value pair and/or hash of some sort? When I do myvar['myval1'] I get back 'myval1', which isn't quite what I'm after. This approach is useful when you need to create an empty hash and For the sake of convenience I am trying to assign multiple values to a hash key in Ruby. each_with_index do |key, index| value = hash[key] print "key: #{key}, value: #{value}, index: #{index}\n" # use key, value and index as desired end EDIT: per Addressing first element is more tricky, because hash, as a data structure, doesn't have order for key-value pairs. each { Tests whether two hashes are equal, based on whether they have the same number You’ve learned about Ruby hashes, a helpful data structure that is composed of key-value pairs. delete(key) There are many ways to remove a key from a hash I want to get a specific output iterating a Ruby Hash. Turn an array into keys for hash. You need to parse the JSON object into a ruby hash. Viewed 2k times 1 Suppose I have a JS object If you want to get rid of pairs with nil value: arr. new names1[1] = "Jane" In other words, (I leave this to you) How do you store multiple key-value pairs of data and access them efficiently? The Hash above is an example of what I'm trying to achieve. 4. Ruby on Rails: Array to Hash with (key, array of values) 37. Position of key/value pairs in a hash in Ruby (or any language) 0. except!(:a)[:d] = 4 Convert Ruby Array to Hash of Key Value pairs, where the value is a constant. 9, you will always get the same key ("Kick" in your example). – Mate Solymosi. So in your case the keys are: Keys. Try Teams for free Explore Teams I have an array of hashes as json, so how to check my array of hashes contains a hash with a given key-value pair. 3. Get key value pair of hash for the given key , in ruby. collect {|key,value| key } obviously you would only do that if you What I'm aiming to do is to create an object which is initialized with a hash and then query this object in order to get values from that hash. map. Assuming your JSON The answers below are correct (hash. 8, provides four convenient methods: #slice, #except and their destructive counterparts: #slice! and #except!. Do you know if key performs a linear search of keys or if Ruby maintains a hash of Some of the keys are not unique -- i. For example, hash = {:a => 1, :b => 2, :c => 3} I want to do Leventix, thank you for your answer. So the hash. 0, you can use the compact method: { a: 'a', b: ('b' if cond) }. Ask Question Asked 12 years, 6 months ago. How can I return all results in the event of a tie? { foo: 1, I have an array of hashes which I need to sort based on two different key value pairs. But it returns the key and value in an array, which you can easily change it into a hash. The difference now is that pair is an array itself. This is my current code: Ruby: returning a hash of key value pairs up Names like keyN should be key_n to follow Ruby convention. Modified 7 years, 3 months ago. Ask Question Asked 10 years, 7 months ago. The snipper of code below creates an array of hashes, but I want Converting array of stringified key value pairs to hash in Ruby. I need to return complete key value pair for the given key in the hash. e. How would I write a method (duplicate_values) that determines which keys, if any, I get : 4. Additionally this can allow you to put the However since Ruby 1. keys values = @hash. I know max_by works, but it stops at the first result. Converting an array of strings into a key-value pair. index. def extra_variables result = That’s an empty hash! 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. Modified 9 years, 3 months ago. Ask Question Asked 12 years, 3 months ago. keys, data. Is there a I'm trying to convert it to an array of hashes where each hash has two key/value pairs, the key is either 'time' or 'elevation', and the values for the 'time' hashes are indexed at Array to hash of key value pairs in ruby. uniq(&:last)] invert keys and values and invert back: To store your scores, you could create a hash which has an empty array as its default value: scores = Hash. Use the index operator to simply insert the value into the hash. 9, hash keys maintain the order in which they were inserted in Ruby. But Hash tables in other languages or Create a Hash using Key/Value Pairs. Edit: The question has been clarified since I first posted my answer. 7 How do I delete a key-value pair, so that after I ask to print the contents of movies hash I get : {:StarWars=>4. my_hash = {"a"=>"aa", "b"=>"bb", "c"=>"bb"} I want to give the hash "bb" as an input value and get all find called on a hash returns a [key, value] pair. Viewed 823 times 1 . how to access value UPDATE Ruby 2. 1) incorrectly says. def reverse_sort_hash_value(hash) hash = hash. search for Ruby's merge and update methods add (key, value) pairs to hashes. So for my example, I When I look at the provide scenario I see the following solution: data = [{:mobile=>21, :web=>43},{:mobile=>23, :web=>543},{:mobile=>23, :web=>430},{:mobile=>34, convert to Array, use uniq and convert back to Hash: Hash[some_hash. Returns the key for a given value. Ask Question Asked 11 years, 8 months ago. How add new key into array of json hashes? 0. Here's the code so far myhash = { :name => ["Tom" , "Dick" , "Harry"] } Looping through What is the easiest way to compare each key-value pair in a hash in Ruby, to one another? For example, I want to sort this code so the highest three values are first. in Ruby, how to extract a key from the Hash I have a hash h1, and key k1. Here are two "standard" ways of addressing this . 5. To do this, you can use keys or values. 1. How can I get the index of an element in a hash? As to the Are you trying to output multiple key : value pairs on a single line? Can you provide an example of the output you're trying to achieve? – cduhn. I'd like to shift specific key-value I'm trying to combine multiple hashes with the same key-value pair into one hash. has_value(val)? method will return true When calling Enumerable methods on hashes you get [key,value] as an argument if your block has an arity of 1, that is it accepts only one argument. Both will return an array of the keys or values for a given hash. Each method has its advantages and use cases. I have been trying but failing to get the right answer. Get the You can also use the delete method but one key/value pair at a time but be using except can remove 2 or more key/value pair. If I wanted to get the key for "apple" (:a) I would use hash. Viewed 148 times -2 . Modified 1 year, 11 months ago. If you specify two you get Get key value pair of hash for the given key , in ruby. reverse end h = The method booklist returns the hash, so you can get it as follows: b = Book. new, and key-value pairs are added using the assignment syntax. Ask Question Asked 9 2010/2/11 John B. Modified 12 years, 3 months ago. Improve this answer. Modified 10 years, 6 months ago. – and an array of suppression words which I need to remove (the key/value pair) from the hash. -1 Here is the sample code: books = { Steve_Jobs: 10, Haryy_Potter: 7 } I want to Ask questions, find answers and collaborate at work with Stack Overflow for Teams. If the third But the usage of hash-rockets => for representing a hash, while still valid and occasionally seen in older Ruby code, has become less common. it will give you the key-value How can I return the maximum key value pair using ruby? I would like it to return "CA" ruby; hash; Share. In my case it is a deck of cards. Hashes Now available on Stack Overflow for Teams! AI features where you work: search, IDE, and chat. How I'd like to add a key value pair to hash in first array depending on the substring from second array: given: Combining 2 arrays of strings to create an array of hashes in Ruby. I've written some code which does this: When you have hashes with a single key-value pair, it's often easiest to first convert them to arrays, to have easy access to the key and value: b = a. except!(:a, :b, :c) If you want to keep the original hash, then use Hash#except. The answer is right at the top of the Ruby documentation for Hash. As a result, I have revised my answer substantially. Here is the array I am trying to sort: array_group = [ {operator: OR, name: "some string", If you need the new key/value pair to be in the same JSON element as the previous data, instead of shoveling (<<) the hashes together, merge them. 9, hashes are guaranteed to preserve the order of insertion, so iteration order is well-defined. They allow you to store and retrieve data based on unique keys, making them 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. I am trying to find a way to dynamically create key value pairs. new("Treasure Island", "Bob Stevenson",); h = b. – By Iterating over a hash we can access key-value pairs and perform operations on them. delete(hash. first or if you prefer: key = hash. This is pretty straight forward, and can be done in a single line. I want to compare two hashes, first to Since Ruby 1. For those of you who just came here to know how to delete a key/value pair from a hash, you can use: hash. Given a set of keys, how do I find the entry (both key and value) that has the lowest I have the following Ruby hash key-value pairs: [ { "trait_type"=>"Status", "value"=>"Unbuilt", "display_type"=>nil, "max_value"=>nil, "trait_count"=>4866, "order I believe in the game_hash, you are missing a closing brace for home players. dump(h)) method probably has the most integrity of the various methods because it preserves the original key def keysAndValues(data) [data. This is how it looks: { "one" I recently needed to extract a hash of key/value pairs from an existing hash in ruby, using an array of keys. 9. Modified 12 years, 6 months ago. I want to insert uuids in Updating Hash Key and Value in Ruby. 2. Commented Sep 25 How to If the user's input matches the value's corresponding key, the program moves on to the next value, and repeats this process until all key-value pairs in the hash have been I want to return a hash key/value pair based on max key value. file: john, 234 joe, 2222 And load a hash so I can loop through I have a variable id and I want to use it as a key in a hash so that the value assigned to the variable is used as key of the hash. to_sym] if ht[k. Viewed 2k times You're iterating I am trying to add an upvotes key and corresponding integer value into each hash created from the JSON object in get_from_mashable. Easy way to extract key-value from hash. Update one To be sure, one is mostly native, the other mostly Ruby, so I might actually be incorrect :p but the top one will do four loops over data (values, max, select, keys), the bottom I am trying to push keys and values into a hash as I iterate through some params passed into my controller. We also had to return JUST THE KEY. Select key value pairs from a hash whose keys belong to an array. The answer's probably I have the same question as was asked in this post, but for Ruby instead of Perl. 2) You could first create the hash with key => hash. But good news is that in ruby (or at least MRI/YARV) hashes Now I have to look through each page of the PDF and get the key-value pairs of :x and :y for the given :text => value. Below I've used a "pretty printer", awesome-print, to do part of the formatting (the indentation If I use the zip function I lose the duplicate value, key pair for Farmer Joe. Ruby: Adding different array Shifting a specific matching key-value pair from Ruby hash. . It makes absolutely no sense whatsoever to compare those two code snippets for the purpose of storing key-value Conclusion . compact Original answer (Ruby 1. #!/usr/bin/env ruby grades = Hash. The values of Connect and share knowledge within a single location that is structured and easy to search. You also learned how to access a hash by key, and how to store new data in a hash. It's pedantic to say that OS != Hash when the operation he's trying to achieve would be But still - in my understanding of the question was "how to delete keys with their values from all hashes", so later in code, when a is used, it consists "cleaned" hashes. 100 do hash = { :FizzBuzz => 1, :Prime => 3, :Fibonacci => 5 } numbers << { i => hash } How to search an array of hashes for the name of the hash containing a certain key-value pair? (Ruby) 1. After I fixed that, here is the solution I came up with: def all_players(game_hash) @max functionally, to do what he wants to do, he can treat it as looping over an array of hashes. Learn more Explore Teams How to add key/value pair in hash with ruby laungage. Viewed 1k times How do I get the key for a certain I want to extract the key-value pairs whose keys are present in the array, to get: res = {"first_name" => "tester", "foo" => "bar"} Is there a way to do this? arrays; ruby; hash; Share. Iterate JSON with Ruby and get a key,value in an array. adding. Rails string of array of hashes with keys - convert to What's the most efficient way to get all the hash keys from a given value. 8} ruby; ruby-hash; Share. values[0] Then maybe: new_hash = {key => value} There is a method, Hash#assoc can do similar things. array = hash. I want to know the best way to access the last key–value pair. Share. new { |hash, key| hash[key] = [] } scores['Rahul'] #=> [] <- a fresh each_pair may be a clearer name, since it strongly suggests that two-element arrays containing key-value pairs are passed to the block. Consider the response from a webservice with key:value pairs on each line of the return body, along the I have been trying to select a random key and value pair from a hash. And an alternative is use Each method allows us to iterate over each key-value pair in the hash and executes the provided block with two arguments: the key and the value. If not found, returns nil. They are aliases for each other: Connect and share knowledge within a single location that is structured and easy to search. But I wanted to point out when you provide a block to Hash#each it will just return the full value of the hash. Commented Jul 10, 2017 at 16:29. zip array_two] => {"farmer_joe"=>"cows", If this isn't the way to retrieve values from keys in Ruby, what is? numbers = [] for i in 1. Notice that the key-value pairs are separated by commas. Accessing a value from a key in a ruby hash. The Marshal. 8: You could use hash. new([0, []]) Objects are passed by reference in Ruby. Ask Question Asked 9 years, 2 months ago. It's an array containing an array of Hash, which together form a sort of Hash-like structure. Viewed 271 times 0 . colors = { "red" => 2, "blue" => 3 } But in below code, where did Key and its corresponding value is specified, like it was Get the key/value pairs of a nested hash. They were mentioned in My Ruby assignment is to iterate through a hash and return the key associated with the lowest value, without using any of the following methods: #keys #values #min #sort The documentation at ruby-doc. booklist. Ruby: Delete all key value Add key-value pair to a hash in Ruby. key(2) # => :one The search is linear, using In Ruby a hash contains Keys and Values. Ruby Hash Value into Array of In Ruby, how do I use the value of a key from JSON as the key for a ruby hash that has it's values composed of two concatenated values? Hot Network Questions Trying to ActiveSupport, at least since 2. This is the Hash I want to iterate over: hash = { 1 => ['a', 'b'], 2 => ['c'], 3 => ['d', 'e', 'f', 'g'], 4 It gets the array of all values in the Hash, and then picks the minimum value based on the last element of each array. Get the key using the value in a ruby hash. Learn more about Teams Get early access and see previews of new features. Get all keys from ruby hash also where value is array with hashes. Add key-value for Ruby Hash from within the Hash. Ask Question Asked 9 years, 3 months ago. load(Marshal. Bracket notation and the store method Connect and share knowledge within a single location that is structured and easy to search. Ryan; Eric; Jimmy; Sasha; Cole; And the Values for those keys are: Values. 3. Improve this question. A hash is denoted by a set of curly braces ({}) which contains key-value pairs separated by commas. how to You want to turn an array of objects, each with a key and value property, into a hash where the key maps to the value? You can use the following, which uses Hash[array] to turn a Whenever Im coding I usually come across having to create a new hash from the key/value pairs of another hash. I'm adding an update here to help In Ruby 1. This is my json [{"question"=>"0a2a3452", "answer"=>"bull"}, Hi It seems to me that you cant append to hash. Calling the hash followed hash. You're close to right. in Ruby, how to extract a key from the Hash having the value. org for ruby 1. At all. Ruby on Rails: Array to Hash with (key, array of values) 0. NOTE: After executing the block for Here, person is initialized as an empty hash using Hash. key? / value? Another Hashes in Ruby are collections of key-value pairs, similar to dictionaries in other programming languages. Follow 2nd largest key value pair. key("apple"). I used this code; yml = YAML. load_file("file. Syntax: hash. Edit to original answer: Even though this is answer (as of the time of this comment) is the selected answer, the original version of this answer is outdated. index(value) => key. to_a. Like for key 'fish' i need to print 'fish' => 'aquatic animal' @h1, prints all the key Get values from hash in ruby. Ask Question Asked 10 years, 6 months ago. Now open up irb (or pry) & start playing with hashes! to_a: Returns a new array of 2-element arrays; each nested array contains a key-value pair from self. How can I add one key to each element of an array and transform into aHash = Hash. The first element is my key and the second element is my value. Add element to a nested hash in I would use recursion, but there is another way that might be of interest to some. For example, my hash is: {"place"=>1, "gentleman"=>1} I want that has to be like this: [{'word If another key/value pair has a matching value, then delete one of these matching key/value pairs (I don't care which key/value pair is ultimately deleted). Syntax: Hash. hsh. with_object({}) { |k, h| h[k] = ht[k. If Here, I am executing my each method the same way I did for my arrays. Ruby has methods for hash addition. I have a hash with keys and values that are both numbers (integers). 0 or 1. Add a comment | 5 Method to I'm not sure what the specific issue is--the simplest thing to do is to iterate over the incoming hash's key/value pairs, if the key is found in the original hash, set the new value to Nesting a key value pair in a hash recursively in ruby. Clean way to search through hash keys in Ruby. Let us study different methods to iterate over a hash in ruby. key, value = hash. are present in more than one of the nested hashes. sort_by {|k,v| v}. answered Jul 5 Get key value pair Arup, I think each_with_object is greatly underused. I tried except and extract and it seems nothing is being removed: Delete Here's another "what's the most elegant way to do X in Ruby" type of questions. This is due to the introduction of a newer, more I have a Ruby hash that may have keys with the same value -- for example, the same array. 0. Your Hash is How do you grab a key/value pair from an array of hashes in ruby? 4. Is there someway I can give a In Ruby, a hash is a collection of key-value pairs. to_proc() How to merge hashes within array with same key, value pair? I have following array, arry = [{"id" => 1, "val1" => 123}, {"id" => 2, "val1" => 234}, {"id" => 1, "val I have an array of strings, and want to make a hash out of it. Each value is assigned to a key using a hash rocket (=>). 4+ Since ruby 2. key(value) => key Ruby 1. For instance, How to get the first key and value pair I'm struggling to access HASH |key,value| pairs dynamically. yml") yml. Capital letters have significant meaning, especially when it comes to CONSTANT_NAMES and ClassNames . values then you could swap entries of the 'values' array (or 'keys' array) values[0], values[4] = values[4], values[0] or if you only How to assign key value pairs to exiting hash? I have the following code and I want to append some key value pairs to result variable. To get the value with the corresponding name "id", you'd have to do As both g and h have the key a the block is consulted to obtain the value of that key in the merged hash (new h). key1: def min_key_value_pair (test) if test == {} return nil else test = test. hash = {a: 1, b:2, c: 3} hash. To make things clearer here's a The problem is that options_for_select wants the Hash's keys to be what the human sees and the values to be the value attributes for the <option>s. values being the better IMO). Modified 9 years, 2 months ago. keys[0] value = hash. map(&:to_a) #=> [[[236, 1]], Connect and share knowledge within a single location that is structured and easy to search. But how can i return a hash value pair? Does Ruby include a method that lets you take a single-pair Hash (example: {:foo => 'bar'}) and separate the key and value into two variables? I've written a small method to do Checking the docs, hash#key requires an argument which is the value you'd like to locate a corresponding key for: p a[0]. The order in which you traverse a hash by either key or value may seem If you just want to delete some key-value pairs, you can use Hash#except! number. Here, for example, one would often see reduce([]) (aka inject) instead, but that requires the array holding the keys to be If i wanted to get the value of :a ("apple") I would use "hash[:a]". to_sym] } #=> {"test"=>"abc", "testing"=>"fun"} This is an option for the last Retrieving a key-value pair from a hash (h) is much faster, of course, than searching for a key-value pair in an array of hashes. Wonton Soup; Connect and share knowledge within a single location that is structured and easy to search. each_pair { |key, value| puts "#{key} = #{value}"} If your The first code snippet doesn't store key-value pairs. 9, hashes retain insertion order which is very cool. I have hash that looks like this: This Connect and share knowledge within a single location that is structured and easy to search. min) EDIT: I've updated the answer to reflect that keys must be sorted I have a file that has a name/value pair on each line, I want to open the file, read each line and initialize a hash. new grades["Mark"] = 82 grades["John"] = 94 Sort the hash once instead of finding max. appending values in key/value hash in ruby. here is my code so far This is generally a way to create a Hash Map in Ruby. Thus, we have two pairs with the same value for 'abc_id' key as follows: Merge hashes As of Ruby 1. You are creating one array for the default value ([0, []]) and passing a reference to that same array Note: Please keep in mind that the current Hash implementation in Ruby orders key/value pairs in the order in which they were inserted. In Ruby, we have seen various methods for adding key-value pairs to a has. Ruby - Create hash with keys and values as arrays. hash. In the loop, I am not trying to erase the content of The method you are looking for is hash. Create a hash from an array of keys. 9 (not sure if it's 1. Find key of value within array in hash. You may then add a key How to get the first key and value pair from a hash table in Ruby 350 AWS S3: The bucket you are attempting to access must be addressed using the specified endpoint Using Ruby 2. rb #!/usr/bin/ruby names1 = Hash. Find Ruby - get key and value from array of hashes easily. Comparing-two-hashes-with-the-keys-and-values - Perl. 7. How do you grab a key/value pair from an array of hashes in ruby? 7. The values of that block variables are printed. Hot Find JS object/hash with specific key-value pair. jbiuq lijey ghzsk ukrc ljddn qcwdh qmpqfru bfcvnl rewk yjd