Flatten array of objects lodash. and if it is an array then it should give me key.

Flatten array of objects lodash Dec 3, 2014 · As we know, to flatten the array [[0, 1], [2, 3], [4, 5]] by using the method reduce() var flattened = [[0, 1], [2, 3], [4, 5]]. Sep 27, 2018 · Libraries like Lodash and Underscore. 0, _. Syntax: _. Documentation and examples for Lodash method getGets the value at path of object. values adds an extra level of array. It does this recursively. Note: This method mutates array and is based on Array#reverse. When giving arrays of primitives the numbers are the values that are going to be tested as to the fact that they are unique or not. Instead, you can achieve this without lodash and recursion. Sep 3, 2024 · Lodash's _. Jun 14, 2019 · Flatten an array of objects and get unique keys and values by a repeated date with Lodash? Asked 5 years, 8 months ago Modified 5 years, 8 months ago Viewed 748 times Sep 3, 2024 · Lodash _. 5. This can be useful for tasks like transforming or filtering data in an array. flatMap () method creates a flattened array of values by running each element in the collection through iterate and flattening the mapped results. Parameter: This method accepts single parameter array that holds simple array or array of arrays. This is particularly useful when you have nested arrays, and you want to simplify the structure while retaining control over the depth of flattening. Mar 12, 2019 · 2 You don't need to use recursion if your object isn't multiple levels deep. Discover the power of Lodash for a smoother development experience. zip() Array Method, seamlessly merging arrays for efficient data pairing. Nov 21, 2024 · Optimize your JavaScript code with Lodash _. Jun 30, 2015 · Given input: [{ a: 1 }, { b: 2 }, { c: 3 }] How to return: { a: 1, b: 2, c: 3 } For arrays it's not a problem with lodash but here we have array of objects. For more information on the _. The enumerable properties of arguments objects and objects created by constructors other than Object are cloned to plain Object objects. See full list on techighness. Overall, lodash. There is also a _. This is a response to Daily JavaScript Challenge #JS-31: Flatten Nested Objects. info - a reference guide for Lodash. It provides several functions such as flatten, flattenDeep, and flatMap which allow us to recursively flatten nested objects and arrays. Sep 2, 2024 · Lodash _. flatten (data) function that flattens shallowly. [[object1, object2],[object1],[object1,object2,object3]] Here is a screenhot of the object logged t The Lodash. flatten and _. Note: This method is loosely based on the structured clone algorithm and supports cloning arrays, array buffers, booleans, date objects, maps, numbers, Object objects, regexes, sets, strings, symbols, and typed arrays. flatten is then necessary because _. This article aims to demystify _. fromEntries to transform back in Returns Array `array`. log ('getMen Jul 23, 2025 · In this article, we will learn how to deep flatten an array in JavaScript. I am trying to flatten an array of objects of arrays. forEach, you can get the merge the object [key, value] pairs as follows. The order of result values is determined by the order they occur in the array. Don't touch an entry that has a non-array value When there is an array value, iterate over its elements to return new key-value pairs As a key, join the original key with the action_type As a value, take the value property Because we're using flatMap, we ensure we're not returning a nested list. Streamline your development process with this powerful utility function, designed to boost efficiency in handling nested arrays. Method 1: Using the flat May 25, 2022 · I am trying to use Lodash to split my nested array and create flattened objects. However, now that the JavaScript standard library is catching up to libraries such as Lodash, we can implement many of the functions in simple ways. Enhance performance and readability in your projects with this powerful utility from the Lodash library. reduce(function(a, b) { return a Note that a nested array inside an object won't be affected, which is what you'd expect. And if keys are object then it should use . Arguments Array|Object The collection to iterate over. superObjectName; for (let su Returns Array the new flattened array. _. flatten({name:['abc' I have below this nested object I need to create an array using this object containing keys. It's similar to _. iterating the full array of objects Gets the size of collection by returning its length for array-like values or the number of own enumerable string keyed properties for objects. If customizer returns undefined, merging is handled by the method instead. 0. flatMapDepth() Collection Method. Jul 16, 2012 · Not sure if this is an actual issue since flatten is supposed to work on arrays only -- but it is a difference between lodash and underscore. For example, we might have something like so: May 7, 2021 · Using TypeScript code, I'm trying to flatten an array of objects where each element can contain children: function getMenu (menus:Array<Menu>, name:string | undefined) { console. 9 Lodash has a merge method that works on objects (objects with the same key are merged). Explore examples and detailed explanations. flattenDepth Array Method flatten an array of objects recursively How to deep flatten an array in JavaScript? Flatten object, unflatten object and find n level value and much more Object Utils Flatten Unflatten Values Clone Merge Delete Manage data using path Object to Array conversion Feb 2, 2025 · Here is a way to flatten a deeply nested object using loops and various array methods. Lodash addresses this with the _. Source objects are applied from left to right. Apr 6, 2020 · Lodash has a `filter()` function that lets you filter an array using a custom function. values, Object. The customizer is invoked with six arguments: (objValue, srcValue, key, object, source, stack). spread() to generate a function that flattens to a single array with unique values: Aug 13, 2025 · Introduction Navigating through the complexities of nested arrays in JavaScript is a common task for developers. Need a one liner. lodash. Lodash, a popular utility library, simplifies this with the _. I tried to do a triple nested forEach or map but I got syntax errors and it got kind of crazy. Overview of Array Methods Lodash's array methods can be categorized into several functional groups, each serving different manipulation needs: May 25, 2015 · Hi there, I have the following object/array of objects: Object1: Oct 30, 2024 · Conclusion Flattening nested objects in TypeScript is a common task that can be approached using recursive functions or libraries like lodash. Why This Documentation and examples for Lodash method mergeWithThis method is like _. Use Object. If the resolved value is undefined, the defaultValue is returned in its place. Elevate your development experience with this powerful utility for seamless array handling. fromEntries to transform back in A simple utility based on lodash to flatten and un-flatten nested objects/arrays. By leveraging these methods, developers can write cleaner Apr 4, 2018 · With lodash you can use _. name: "Node JS" Accessing flattened properties: HTML, CSS Node JS Using the Lodash library In this approach, we will use lodash library provided by NPM to flatten the given object. map. Aug 13, 2025 · Introduction Combining mapping and flattening operations is a frequent necessity in array manipulation. . However when having arrays of objects that are also arrays, it is the arrays themselves that are May 18, 2025 · In conclusion, Lodash provides a wide array of utility functions that can greatly simplify and enhance everyday coding in JavaScript. We create an object with nested properties. hobbies and then for each of those objects. Sep 19, 2016 · Does lodash or vanilla JS have a nice way to flatten an object of arrays into an array? Asked 9 years, 1 month ago Modified 2 years, 7 months ago Viewed 943 times Apr 17, 2015 · I have a nested array of objects and want to get only the child property elements of an array. flatMap() Collection Method. Added a breakLoop method to break in the middle of any Underscore iteration. Why This Flatten array with objects into 1 objectGiven input: [ { a: 1 }, { b: 2 }, { c: 3 }]flat ()” method is embedded in ES6 that enables you to “flatten” a nested JavaScript Array. flatten () method is used to flatten the array to one level deep and it returns a new flattened array. Here's what you need to know. Get the pairs from the items object, and use _. These nested structures can complicate data processing, especially when you need a flat array for operations like mapping, filtering, or reducing. : [{ Array and plain object properties are merged recursively. Among these is the _. Not sure what the correct term for this process is. Added an isEmpty function that works on arrays and objects. It's a valuable tool for developers who frequently work with multi Extremely useful if you have to flatten an array inside of an array, since using apply would presume you are passing in an array of parameters. Return Value: Note: This method is loosely based on the structured clone algorithm and supports cloning arrays, array buffers, booleans, date objects, maps, numbers, Object objects, regexes, sets, strings, symbols, and typed arrays. Oct 10, 2021 · Use _. You could use . What is the cleanest way to do it, If I don't know how many nested object Documentation and examples for Lodash method toArrayArray chunk compact concat difference differenceBy differenceWith drop dropRight dropRightWhile dropWhile fill findIndex findLastIndex flatten flattenDeep flattenDepth fromPairs head (first) indexOf initial intersection intersectionBy intersectionWith join last lastIndexOf nth pull pullAll pullAllBy pullAllWith pullAt remove reverse slice Returns Array `array`. flattenDepth() method in Lodash is designed to flatten an array up to a specified depth. flatMap(). May 13, 2020 · Photo by Brooke Lark on Unsplash Lodash is a very useful utility library that lets us work with objects and arrays easily. Jun 16, 2022 · So in the third test, the native JavaScript flat method is almost 90% faster than Lodash flatten method. asPairs then _. In this way, the order of the arrays doesn't matter. Oct 28, 2009 · Chained Underscore objects now support the Array prototype methods, so that you can perform the full range of operations on a wrapped array without having to break your chain. com In this guide, I‘ll walk you through everything you need to know about _. Before diving into the specifics of Lodash‘s implementation, let‘s understand what array flattening actually means. How can I accomplish this using lodash or plain JS? Sep 2, 2024 · Lodash _. This method is designed to reduce the depth of nested arrays by one level, simplifying array manipulation and making data structures more manageable. Test 4: In this test, I want to compare the performance of the sort method in JavaScript and Lodash. toPairs result else result filterObjectByPattern = (src, pattern) -> pattern = new RegExp pattern result = flatten src, asPairs: true Note: This method is loosely based on the structured clone algorithm and supports cloning arrays, array buffers, booleans, date objects, maps, numbers, Object objects, regexes, sets, strings, symbols, and typed arrays. For collection methods that work on both arrays and objects, see Collection Methods. Mar 24, 2019 · The result of this operation becomes the corresponding element in a new Array. values de-references each key in an object, and turns it into an array element holding that key's value. Elevate your development experience with Lodash's versatile _. Apr 12, 2016 · # Note: I polyfill array with some of lodash common methods for better flow flat = require 'flat' flatten = (obj, options = {}) -> result = flat obj, options if options. We log the result of the _. Creates an array of the own enumerable string keyed property values of object. I can use pure Javascript or libraries, I particularly like underscore. Discover how to efficiently flatten nested objects and arrays in JavaScript using Lodash or a simple recursive function. flattenDeep() Array Method. This can be immensely useful when dealing with arrays containing various levels of nesting, making data more accessible and manageable. zip() method. Here, the “Array” object will invoke the “flat ()” method while passing “depth Sep 2, 2020 · 2 - Nested Objects with the lodash union, and lodash flatten methods If I use a method like lodash union in a project I might run into problems with nested objects. flatten, then iterating resulting array vs. Jun 18, 2015 · I have the following collection. flattenDeep Array chunk compact concat difference differenceBy differenceWith drop dropRight dropRightWhile dropWhile fill findIndex findLastIndex flatten flattenDeep flattenDepth fromPairs head (first) indexOf initial intersection intersectionBy intersectionWith join last lastIndexOf nth pull pullAll pullAllBy pullAllWith pullAt remove reverse slice sortedIndex sortedIndexBy sortedIndexOf sortedLastIndex Oct 9, 2015 · I need to flatten a nested object. An empty object is returned for uncloneable values such as functions, DOM nodes, Maps, Sets, and WeakMaps. In this demo, the arrays a and b are first converted into objects (where userId is the key), then merged, and the result converted back to an array (_. flattenDeep( array ) Parameters: This method accepts single parameter as mentioned above and described below: array: This parameter holds the array that to be flatten. Enhance data manipulation and simplify array operations with this powerful utility, boosting performance in your web applications. toPairs() to get an array of [name, items] pairs, which you iterate with _. Lodash’s modular methods are great for: Iterating arrays, objects, & strings Returns Array the new array of grouped elements. in syntax is used to loop through key-value pairs in a POJO (plain old JavaScript object). In the vast landscape of programming, the ability to transform complex structures into streamlined data is invaluable. So basically, studies array is put into its own variable and rest will be an object with all the remaining properties. Effortlessly flatten and map arrays in a single function, streamlining your data manipulation. Thanks to the continuous evolvement of the ECMAScript standard, we’ll now be getting methods to do that directly in vanilla JavaScript, without the need for external utility functions. Return Value: This method returns the new flattened Nov 4, 2020 · Is it possible to flatten this collections using lodash and concatenate the path strings? I tried to but can only reach second level, I want to flatten it regardless the depth as long as there's a pageRouter array inside the object Feb 13, 2018 · Hot to flatten nested array of objects using lodash? Asked 7 years ago Modified 7 years ago Viewed 3k times Feb 17, 2025 · Master Lodash Reduce for Efficient Nested Array Handling Master Lodash Reduce to effortlessly manipulate nested arrays, streamline your JavaScript coding, and enhance your development efficiency. Creates an array of grouped elements, the first of which contains the first elements of the given arrays, the second of which contains the second elements of the given arrays, and so on. Creates an array of unique values, in order, from all given arrays using SameValueZero for equality comparisons. If you try to flatten an object: _. Subsequent sources overwrite property assignments of previous sources. prototype. Lodash makes JavaScript easier by taking the hassle out of working with arrays, numbers, objects, strings, etc. Nov 21, 2024 · Optimize data manipulation with Lodash's _. flatten () function to flatten the object. How to flatten nested object? Jul 23, 2025 · technology. Recursively flatten array up to depth times. flatten method of lodash. dot syntax. Note: Non-object values are coerced to objects. Lodash helps in working with arrays, strings, objects, numbers etc. Mar 8, 2018 · How can I flatten matches into single array of objects or actually have flat structure where all nested items are in single array or object ? I have managed to get so far by wrangling data but seem stuck at this I can use pretty much any library or tool and latest JS features. Mar 20, 2015 · I have an array which contains several arrays, each containing several objects, similar to this. iterate: This parameter holds the function invoked per iteration. Flattens array a single level deep. Lodash is a JavaScript library that provides utility functions for common programming tasks. What is Array Flattening? Lodash Flatten Method - Learn how to use the Lodash flatten method to create a one-dimensional array from a nested array structure. Possible duplicate of Underscore to flatten nested array of parent/child objects This talks about underscore, but should work for lodash too. Reverses array so that the first element becomes the last, the second element becomes the second to last, and so on. Since 0. reduce() callback. Checks if value is classified as an Array object. Function The function invoked per iteration. flatten, flattenDeep or flattenDepth of lodash only accept array. Nov 9, 2025 · Lodash, a popular JavaScript utility library, provides a wealth of helper functions to streamline common tasks like iteration, transformation, and manipulation. map() to create the arrays that include the info: Aug 13, 2025 · The Lodash library, a mainstay for developers, offers a suite of utility functions to simplify array and object manipulation. union() and _. Returns boolean `true` if `value` is an array, else `false`. flatMap () method, which first maps each element using a provided function and then flattens the result into a new array. merge except that it accepts customizer which is invoked to produce the merged values of the destination and source properties. In this guide, we’ll explore how to use Lodash to flatten nested objects (and arrays!) step-by-step, with practical examples and best practices. keys, and Object. Understanding the structure of your nested objects and choosing the right technique will help you efficiently flatten complex data structures. Only bummer is if you have arrays inside your array that are more than two levels deep. Each object may have a children array of objects, which may have a children array of objects and so on Nov 21, 2024 · Optimize your JavaScript code effortlessly with Lodash _. Flatten nested arrays seamlessly, enhancing performance and readability. Perhaps you are wanting to remove a level of nesting from items in arr ? Documentation and examples for Lodash method flattenDeepArray chunk compact concat difference differenceBy differenceWith drop dropRight dropRightWhile dropWhile fill findIndex findLastIndex flatten flattenDeep flattenDepth fromPairs head (first) indexOf initial intersection intersectionBy intersectionWith join last lastIndexOf nth pull pullAll pullAllBy pullAllWith pullAt remove reverse slice Say I have the follow array of objects storing a single key\\value pair: var someArray = [ {foo: 1}, {bar: 2} ]; I would like to flatten this array into a single object, where each key from Nov 21, 2024 · Optimize your JavaScript code with Lodash's _. This is just an example and the actual data will include a unique children property in separate indice Nov 20, 2018 · I need to filter objects recursively in a deeply nested array of objects using javascript, maybe with the help of lodash. See the ES spec for more details. We will explore the uses, syntax, and real-world applications of _. Elevate your programming experience with seamless array transformations. Your attempt of arr[0] simply accesses the first item in the array. Jul 10, 2025 · The flat() method of Array instances creates a new array with all sub-array elements concatenated into it recursively up to the specified depth. flatten, which can be used to flatten a JavaScript object. values) (getting rid of the keys). I was able to use pure Javascript to do so, but I would like to use Lodash instead. As you may have seen if you’ve been following the interwebs lately, these new methods We import the lodash library into our code using the require () function. Jul 23, 2025 · Lodash is a JavaScript library that works on the top of underscore. 58 Create dictionaries for both arrays using _. stats and then spit it out all in 1 new array. Array and plain object properties are merged recursively. flattenDeep () Method The _. The flattening of an array is a process of merging a group of nested arrays present inside a given array. Array|string The path to check. The object might contain arrays as values Object { 0: [1,2,3,4] } to [0,1,2,3,4] convert Dec 26, 2018 · I'm looping over object with a property set to array, which i then use in the following way: let merged= []; for (let sup of superObject) { let sname = sup. Simplify complex structures and streamline your data manipulation tasks. To convert Objects into Arrays: you can use Object. flatten () function, please see the Lodash documentation. 0 Arguments object (Object): The destination object. Returns Object the new object. Nov 18, 2019 · I've been trying to create a generic function which could flatten an array of objects but am failing at every turn. Note: This method mutates object. and if it is an array then it should give me key. Efficiently flatten and map multi-level structures, enhancing code readability and performance in JavaScript projects. Aug 13, 2020 · The groupBy method returns an object that takes the items in an array, calls an iteratee function and add that as the key of the returned object]. flatten () method is used to flatten the array to one level deep. flatten() method in Lodash is designed to flatten nested arrays, reducing multi-dimensional arrays into a single-dimensional array. Creates a duplicate-free version of an array, using SameValueZero for equality comparisons, in which only the first occurrence of each element is kept. Note: This method The one-page guide to Lodash: usage, examples, links, snippets, and more. flatMap The Lodash flatMap method You can flatten an array to the first level then you can use the _. Does anyone know of any existing function which could Returns boolean `true` if `value` is an array, else `false`. Aug 13, 2025 · The Lodash library, a mainstay for developers, offers a suite of utility functions to simplify array and object manipulation. Documentation and examples for Lodash method flatMapArguments Array|Object The collection to iterate over. Aug 13, 2025 · Introduction Dealing with nested arrays in JavaScript can often lead to complex and verbose code. flatMap to get each job array, and then create an individual object for each item within that job array using . Firefox < 10, IE compatibility mode, and IE < 9 have buggy Array shift() and splice() functions that fail to remove the last element, value[0], of array-like objects even though the length property is set to 0. sports, and for each of those objects need to el. SO basically I want to "flatten" each element of the array, in a way such that object keys are determined based on the main and subkeys. Nov 21, 2024 · The _. Returns Array the new duplicate free array. flattenDeep () method is used to completely flatten nested arrays. Array the new flattened array. Simplify your routing structure toda Feb 8, 2016 · I got following data structure, which is an array of accounts objects, where some accounts are being parents to its children accounts, which in turn can be parents to other accounts etc. In this article, we’ll look at how to create our own methods to flatten collections. flatMap is a convenient way to apply a mapping function to each element of an array and flatten the resulting arrays into a single array. Learn how to use the Lodash flatten method to create a one-dimensional array from a nested array structure. library. keyBy(), merge the dictionaries, and convert the result to an array with _. flatten() method in Lodash flattens an array to a single level deep. flatMapDeep() Collection Method, streamlining nested arrays and objects. Return Value: The return type of this function is an array. Oct 26, 2021 · You could use flatMap to iterate the object's entries. flatten () function to the console. flatten () – from basic usage to advanced techniques that will level up your code. flatten () method. flattenDepth () method, a versatile tool for flattening nested arrays up to a specified depth. When working with JavaScript, you often encounter nested arrays—arrays that contain other arrays as elements. Documentation and examples for Lodash method mergeWithThis method is like _. values and using Array. Edit this code on GitHub Nov 22, 2024 · Optimize your JavaScript code with Lodash's _. This method is a powerhouse in unraveling layers of nested arrays, transforming them into a single-level array. These functions allow you to flatten Apr 23, 2016 · Since Lo-Dash 3. flattenDeep, to simplify this task. Lodash Array methods are used to perform operations on arrays using inbuild methods. Arguments Object The object to query. Sep 16, 2020 · Iterate through Nested Object's properties to flatten in an array using ES5 or lodash Asked 4 years, 6 months ago Modified 4 years, 6 months ago Viewed 381 times We import the lodash library into our code using the require () function. See example below: Detect if Array#shift and Array#splice augment array-like objects correctly. entries. Other objects and value types are overridden by assignment. Deep flattening means that the array would be completely flattened. you need to go el. flatMap(collection, iteratee); Parameters: collection: This parameter holds the collection to iterate over. js have provided us with utilities to help with flattening arrays for a while now. Example: Input: [1,2,3,4,5,[6,[7,8,9]]] Output: [1,2,3,4,5,6,7,8,9] This can be done using the following methods. Creates an object composed of the picked object properties. Apr 18, 2025 · This page documents the array-focused methods available in Lodash, their behavior, parameters, and common usage patterns. js. This method returns a new array in which all of the elements of sub-arrays are concatenated according to the specified depth. flattenDeep () method. flatten( array ); Parameter: array that holds a simple array or array of arrays. The Lodash library offers a neat solution with its _. One of the functions it provides is _. This new Array is what's returned. Description Comparing Speed of lodash's _. Then it creates an array as the value for each key, and then push the items that are the same as the key when iteratee is called with it into the array. JS isn't my home language. flatMap (), exploring its application, syntax, and utility through detailed examples and FAQs. Object. flatMap () but allows control over the flattening depth. values(). I have written this small function to get all keys and values of an object and store them into an array. I've got Aug 6, 2025 · Lodash _. Then we use spread syntax for array literals to put the members of the current accumulator array as well as a mapping of the new objects from studies into the callback result May 12, 2020 · Lodash Methods Implemented with Plain JavaScript — Flattening Arrays and Searching Lodash is a very useful utility library that lets us work with objects and arrays easily. The _. flatMapDepth () method flattens an array by applying a function to each element and recursively flattening the results up to a specified depth. Nov 21, 2024 · Optimize your JavaScript code with Lodash's _. Aug 29, 2019 · What do you mean by dereference? The original object is an array with two items. Effortlessly flatten and map arrays to a specified depth, enhancing performance and simplifying complex data manipulation. In addition, it can also handle arrays of different length. With some ES2015 and LoDash/Underscore Returns Array the new array of combined values. You have an array of objects in the top layer, then you need to go into el. flattenDeep (data) will return a deeply flattened array as you desire. Nov 10, 2017 · This uses the new rest syntax for object literals in the second parameter to the . Nov 5, 2020 · You can get values of object using Object. Sep 15, 2017 · Recursive functions is the way to go for any depth of iteration. Principles used: Looping through an object: For. Lodash provides two powerful utility functions, _. Creates an array of the own enumerable property names of object. We use the _. brsr jqjimm ryth gzonoe ltp toj gctt wgmsud vsdcyxg mwtd smefnyo suaaq epmwdf muzro iivmf