Merge arrays in ruby. Modified 7 years, 1 month ago.

Merge arrays in ruby. The concat() method allows you to append elements from one array to another, Array#concat () : concat () is a Array class method which returns the array after appending the two arrays together. Then you just have to pull out the second (or last) elements of the inner arrays with v. I am trying to write a ruby method which performs a merge sort recursively. The other array has his job and age. 0, it says: Ruby merge array conditionally [closed] Ask Question Asked 7 years, 1 month ago. merge!() Parameter: Hash values Return: add the content the given hash array to the other Example #1 : # Ruby co I have a few arrays of Ruby objects of class UserInfo: class UserInfo attr_accessor :name, :title, :age end How can I merge these arrays into one array? A user is identified by its name, so I want no duplicate names. dup. Program Steps. This question needs to be more focused. the C extension was always fastest and roughly 2-3x faster than concat; plus is getting really slow if you concatenate many arrays; Conclusion. a. Stack Overflow. I am trying to merge information from these two separate arrays that have information for the same person. 3. sawa. If the arrays always contain a single hash, the arrays serve no purpose and we might instead just reference the hashes: Merge Ruby Arrays into Multidimensional Array. Since very_huge_array (operator) another_very_huge_array possibly yields yet_another_very_huge_array, (a1|a2)-(a1&a2) can creates two huge arrays which merge(p1) public Returns a new hash containing the contents of other_hash and the contents of hsh . Combining arrays of arrays in ruby . Also: pry with show-source rocks! Try for yourself: Also: pry with show-source rocks! Try for yourself: $ Array. So call it by putting. new{|hash, k| hash[k] = []}) do |memo, i| memo[i. In the first form, if no arguments are sent, the new array will be empty. instance_methods. It is not currently accepting answers. Hot Network Questions How to mount a . Although "2-3x" sounds like a huge improvement, it's just a few milliseconds in absolute terms. Merge Ruby nested hashes with same keys . I have this starting array of arrays: [["6884", true], ["8456&qu Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Now, you'll presumably want to pad the arrays with as many nils as needed, and then perform the same operation as above: max_length = [a,b,c]. def merge_arrays(a, b) # build a holder array that is the size of both input arrays O(n) space I am not sure what do you mean by "merge" (there is no #merge method on arrays, only on hashes), but you can simplify your code like this:. How to merge 2 arrays into third array. Rails 4 how to merge 2 arrays. Merge arrays inside of arrays. Hot Network Questions Explanation Request - Stephen Abbott's Understanding Analysis proof that √2 exists Hex diff encoder Integration test for a script that writes a YAML file Why doesn't --cycle goes I'm having a hard time grasping the logic I'd need to merge two arrays of hashes, It seems I've asked this question a while back in sort of a different way, I've also tried a few other things like the answers offered here: merging arrays of hashes. first] << i. Modified 7 years, 1 month ago. merged_array = arr1 + arr2 + arr3 + arr4 => [9, 8, 5, 3, 1, 16, 14, 12, 10, 4, 47, 35, 28, Combining arrays is a common operation when you need to merge multiple arrays into a single array. reduce(0, :+) While equivalent to array. Provide details and share your research! But avoid . Best possible way to get two arrays merged. Ruby provides the concat method and the + operator for this purpose. zip( padded_array(b, max_length), padded_array(c, max_length) ). Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Visit the blog Order doesnt matter because i have to shuffle the array as well after its all merged - but the merge using sets is slower than the merge using concat which is the fastest method weve been able to come up with thus far. asked Jul 13, 2015 at 14:32. How to merge two array objects in ruby? 1. You need to create pipeline using recursion going to crunch through each array. checking at each iteration to see which value at index 0 of either array is lower, removing that from the array and appending that value to the result array. If name, title, age, etc. 114k 14 14 gold badges 156 156 silver badges 228 228 bronze badges. If the arrays always contain a single hash, the arrays serve no purpose and we might instead just reference the hashes: Ruby arrays can hold objects such as String, Integer, Fixnum, Hash, Symbol, even other Array objects. max def padded_array(array, size) array. Concatenating multiple arrays in ruby. If I start with two arrays such as: array1 = [{"ID":"1","name":"Dog"}] array2 = [{"ID":"2","name":"Cat"}] How to merge this array into one array like this? arraymerge = Understanding how Ruby handles blocks and arguments can seem daunting at first, especially when trying to decipher code that involves methods with seemingly complex You can add arrays to merge them in ruby. The regular flatten method will return a new Array, which you assign to result in your case. 6. merge array with array of arrays. The question, essentially, is "how to concatenate arrays in Ruby". inject(0, :+), the term reduce is entering a more common vernacular with the rise of MapReduce programming models. We will call it merge. 2. Concatenating existing values within the same array in Ruby. The In Ruby, zip is a way to combine elements from two different arrays, albeit in a way that is slightly difficult to understand at first glance. Even though arr1 and arr2 each contain a single element (a hash), the code above works fine when the arrays contain multiple hashes, and when there are more than two arrays. h = ary. Combining Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Visit the blog I would like merge 2 arrays with different data inside. Any sort of help understanding this would be really helpful to me. There are Using the non-bang method will leave dest's internal values alone when an unmergeable entity is found. Ruby: How to concatenate array of arrays into one. Ruby arrays grow automatically while adding elements to them. If names are the same, but any of the other Assuming you have two sorted arrays. Entries with duplicate keys are overwritten with the values from each other_hash successively if no block is given. Hot Network Questions Explanation Request - Stephen Abbott's Understanding Analysis proof that √2 exists Hex diff encoder Integration test for a script that writes a YAML file Why doesn't --cycle goes . Additionally- just another Ruby tip, you do not need the destructive flatten! with ! versus the regular flatten. For example the above should be [["A", "B", "C", The simplest way to combine these arrays and sort them is to just the plus operator. How to merge two array objects in ruby? 3. Skip to main content. When a size and an optional default are sent, an array is created with size copies of default. So I want to like merge them so that for every item in the first array (days_to_report), has the data that the second array has too, like the ideal output would be: (notice the data for the date for Sun, 03 Apt 2011) array. Combining arrays in Ruby. map do |name, email| Item. Hier sollte eine Beschreibung angezeigt werden, diese Seite lässt dies jedoch nicht zu. Ahkshay Ravi Ahkshay Ravi. Returns a new array. Merge two hashes with arrays by the same key Ruby. Lucasio Array#&() is a Array class method which performs set intersection operation on the arrays. names In array. Ruby Array Elements Merging. In this article, you will learn how to use the concat() method or the + operator to achieve this. this is the problem statementyour solution would not work in this case. I find consistency across your code base most important, but since various communities tend to How would I merge these arrays together so that the output would be ["Person One 24", "Person Two 25", "Person Three 26"] Thanks. Assuming you have an Item class whose initialize methods We just need to call the merge sort recursively on the original array, and use our merge method to merge all the divided sub-arrays back into one final, sorted array. Also, notice the usage of block syntax of Hash#new which Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company I am working on a Ruby gem to pull data from the Wikidata API. (I think) Merge Sort in Ruby. How to merge hashes in a Even though arr1 and arr2 each contain a single element (a hash), the code above works fine when the arrays contain multiple hashes, and when there are more than two arrays. Return: Append the Arrays are the Swiss Army Knife of data structures in Ruby. Return: Common elements from both the arrays. are equal I'd like to have 1 entry in the new array. It's msort that should take the unsorted array as a parameter. fill(nil, array. Ruby: How to create an array by combining and interleaving two other arrays. It handles arbitrarily deep merging of hashes containing whatever data structures. Stack Overflow . reduce(Hash. Alessandro Allegranzi · Follow. inject to massage the data array into a hash. One array has his name. ruby array of hash merge array values based on key. Naturally the answer is to use concat or + as mentioned in nearly every answer. zip(b) should do – Santhosh. – Abhinay Commented Aug 7, 2017 at 8:38 Then the group_by partitions the combined array by the first element so that the inner arrays can easily be worked with. push(*new_array) end update_array(a2) arrays; ruby; merge; Share. As of Ruby 2. Result. How can I do this inside an Order doesnt matter because i have to shuffle the array as well after its all merged - but the merge using sets is slower than the merge using concat which is the fastest method weve been able to come up with thus far. About; Products OverflowAI; Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, Basically, I want to "merge" the array values of same named keys when the values corresponding to those keys are arrays. So in your case you'd iterate over the outer array and use . About; Products OverflowAI; Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & First element of array ["GJ","MP"] Added is in the answer_string = "GJ, MP" Now Find MP which is the last element of this array in the other where is should be first element like this ["MP","KL"] after this I have to add KL in to the answer_string = "GJ, MP, KL" This is What I What is the Ruby way to achieve following? a = [1,2] b = [3,4] I want an array: => [f(1,3) ,f(1,4) , f(2,3) ,f(2,4)] Skip to main content. zip(@emails). merged = sources | external_sources To make it work with your class, you need two more methods: #hash (instance hash value, used for preliminary equality screening), and #eql?, used to confirm equality: Inject combines all the elements in an array using a method (or block). Merge items of two arrays into new array . I have the method working, but It's one of those times where I accidentally got it working so I have no idea WHY it works, and would love to understand how the code I have written works. Follow edited Mar 23, 2016 at 7:17. 85. 168k 49 49 gold badges 284 284 silver badges 395 395 bronze badges. I've created another benchmark, comparing +, concat and a custom C extension with a variable number of arrays. Follow edited Jul 13, 2015 at 14:38. iso Ruby Array Elements Merging. 0. inject, reduce, fold, accumulate, and compress are all synonymous as a class of folding functions. If no block is specified, the value for entries with duplicate keys will be that of other_hash . Both arrays have an id matching to the same person. Merging two Arrays together. flatten! will flatten self in place, altering whatever Array it's called upon, rather than returning a new array. flatten. arrays; ruby; Share. How to merge array of hashes with nested array. The second form creates a copy of the array passed as a parameter (the array is generated by calling to_ary on the parameter). One way is with the new class method −. Ruby. Hot Network Questions Define a command with keys as arguments AND allow the default values depend on each other Getting a +5 V supply from a negative 48 V , non-isolated (Telecom) Get histogram of bytes in any set of files in Java - take I'm new to Ruby on Rails and I have a weird array situation that I'm unable to figure out how to execute efficiently. Me guess that keeping polymorphic values (sometimes 7, sometimes [ 7, 7 ]) is not such a good practice. 8. I would like to merge the two arrays, then remove the values that is the same with other array. 15. Define two arrays. @list = @names. Stefan. map(&:length). The documentation is a bit opaque, at least If you have two arrays and want to join or merge them into one you can do it like this: # Faster, because this changes the users array users. Learn the best and most efficient methods here. 3k 39 39 gold The merge method is for merging together 2 sorted arrays, a and b. Whether you‘re iterating over elements, manipulating order, grouping data, or extracting subsets – knowing the right What is the simplest way to merge the array items that contain members that are shared by any two or more arrays items. map(&:last) and sum them with inject(:+). Hot Network Questions British Children's Educational Ruby group array of arrays to merge them into one single array based on unique key in arrays. 4. amalgamate two ruby arrays. * ($ is shorthand for show-source) Merge Ruby arrays and concatenate elements in it. Rails merge array into array of arrays. first; memo end Note that we are using Enumerable#reduce to collect the values in a new Hash. . &() Parameter: Arrays for performing the intersection operation. values. Consolidating Multidimensional Array in Ruby. So if I will add to the existing array this array ['Area1', 33441] I want either to merge the array like this [['Area1', 12345, 33441], ['Area2', 54321]] or to display the information like this: Area1: 12345, 33441 Area2: 54321 . Parameter: Arrays to be combined. How to merge groups of arrays? 1. concat(new_users) # Slower, You can use zip to zip together the two arrays and then map to create Item objects from the name-email-pairs. Of course the following will replace hash_1's :stuff1 array with hash_2's :stuff1 array (and similarly for :stuff2), but I want an array '+' type of merge, not an update/replace, or merge! I am wondering how to merge these two arrays into one clean array in Ruby Both arrays share one similar key:value pair. keys. Ruby arrays are not as rigid as arrays in other languages. Example #1 : # Ruby code for &() method # showing intersection operation # decla I need a method which returns a merged array starting a specified index. new(:name => name, :email => email) end Merge Ruby arrays. Merging an array of hashes. Hot Network Questions About Jesus's reading of Isaiah in the synagogue Understanding the parabolic state of a quantum particle in the infinite square well Has anyone returned from space in a different vehicle from the one they went up in? And if so who was the merging 2 array in ruby. Merging a nested hash without overwriting. Use the + operator to merge The array + operator in Ruby provides a shorthand for merging arrays without mutating the originals: [1, 2] + [3, 4] # => [1, 2, 3, 4] This syntax essentially concatenates two There are a number of ways to combine arrays in Ruby. Commented Mar 23, 2016 at 7:01. Passing :merge! to it causes each iteration to destructively merge the hash so you don't have the waste of creating little hash copies as it goes. c the first thing Ruby does is checking for a string type and then calling the join method. asked Mar 23, 2016 at 6:59. For example: I want to merge them into one array of hashes, so essentially a + b except I want any duplicated key in b to overwrite those in a. Richlewis Richlewis. While the OP has been criticized for lack of research effort, it should be pointed out that the Ruby documentation for Set#merge is not friendly for new Rubyists. 1. Lots more docs on Daniel's github repo now. Combining arrays of arrays in ruby. Why not just keep this in a single hash of arrays rather than an array of hashes whose values are sometimes arrays? – Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company merging ruby hash with array of values into another hash with array of values. Asking for help, clarification, or responding to other answers. How to combine one-dimensional ruby arrays into a two-dimensional array? 6. Hot Network Questions How long should a direct quote be in order to be put in quotation marks? Why This Question is Useful. Hot Network Questions Vim switches buffers autonomously RandomVariate sometimes returns the input instead of the numbers How much of its receive You can use zip to zip together the two arrays and then map to create Item objects from the name-email-pairs. Merge a single array into nested array in rails. And I do have to use arrays because im merging an ActiveRecord dataset from the db, which is an array. Making two-dimensional array from array in Ruby. Creating Arrays. I've looked here, here and here without cracking it. 49 1 1 silver badge 6 6 bronze badges. Improve this question. Here's the first array : [ [Wed, 30 Mar 2016, 2], [Fri, 01 Apr 2016, 1], [Sat, 02 Apr 2016, 1], [Sun, 03 Apr 2016, 1] ] And here is the . I can see that this concatenates but I want to update the array not simply combine them: @a1 = [0,0,0,0,0] a2 = [1,1] def update_array(new_array) @a1. merge array with array of arrays . Follow edited May 23, 2017 at 18:46. The data is deeply nested, as it contains a lot of repetition. Assuming you have an Item class whose initialize methods accepts a hash, the code would look like this:. Combine two arrays with prepend. I have written a piece of Ruby (sans Rails) code that enables an array of hashes to be merged together, with any duplicate key-value pairs being stored as an array under the same key. It is used by the sort algorithm in msort. compact Step 2: We now have array of hashes, let's merge the hashes such that for a given key, the values are collected as array. Hash#merge!() : merge!() is a Hash class method which can add the content the given hash array to the other. It will add the arrays contained in :x together because it knows how to merge arrays. Syntax: Hash. Syntax: Array. p msort([6,1,8,4,9,3]) at the end of the file. Take notice that all elements will reference the same object default. Viewed 738 times -1 Closed. I am wondering how to merge these two arrays into one clean array in Ruby Both arrays share one similar key:value pair. merging 2 array in ruby. 3 min read · We want to build a method that given two arrays can merge them into one array in order. length, size) end padded_array(a, max_length). A natural extension to the In this article, we’ll explore various techniques to merge arrays in Ruby, discussing the syntax, functionality, and use cases of methods such as concat(), the + operator, push() with a splatted array, append(), union(), and In Ruby, there are multiple ways to merge arrays, but this post will guide you through one of the simplest methods. In this case, both a and b contain a key 1 and I want the final result to have b 's key value pair. And returns the common of the two arrays. Ruby: Merge Hash containing Arrays. There are many ways to create or initialize an array. (I think) Thanks for contributing an answer to Stack Overflow! Please be sure to answer the question. Does anyone have any idea if is this possible in rails? Thank you! ruby-on-rails; arrays; Share. 3. Merging hashes into arrays.