A short-hand way to do it is to convert it to an array via the ES6 spread operator.
Then all the array functions are available to you.
const mySet = new Set([1,2,3,4]);
[...mySet].reduce(...);
Top answer 1 of 5
267
A short-hand way to do it is to convert it to an array via the ES6 spread operator.
Then all the array functions are available to you.
const mySet = new Set([1,2,3,4]);
[...mySet].reduce(...);
2 of 5
30
To sum up the discussion from comments: while there are no technical reasons for set to not have reduce, it's not currently provided and we can only hope it changes in ES7.
As for map, calling it alone could violate the Set constraint, so its presence here might be debatable.
Consider mapping with a function (a) => 42 - it will change the set's size to 1, and this might or might not be what you wanted.
If you're ok with violating that because e.g. you're going to fold anyway, you can apply the map part on every element just before passing them to reduce, thus accepting that the intermediate collection (which isn't a Set at this point) that's going to be reduced might have duplicated elements. This is essentially equivalent to converting to Array to do processing.
AG Grid
ag-grid.com › ag grid › javascript data grid › set filter - overview
JavaScript Grid: Set Filter - Overview | AG Grid
The following filter parameters will reset the Set Filter - treeList, treeListPathGetter, caseSensitive, comparator, and excelMode. Additionally, a few column definition properties will also reset the Set Filter - filterValueGetter, keyCreator (unless specified in both the old and new filter parameters), and valueFormatter (if no keyCreator and the Cell Data Type is not 'number' or 'text').
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JavaScript Basics - How to use the filter method - YouTube
DEV Community
dev.to › swarnaliroy94 › understanding-map-filter-set-and-the-spread-operator-in-javascript-49ko
Understanding map(), filter(), Set, and the Spread Operator in JavaScript - DEV Community
September 13, 2025 - The condition given inside the function (num => num % 2 === 0) simply means that only even numbers should be returned. So .filter() will go through each element in the array numbers and return a new array keeping only the even number elements. A Set ...
Shaunhartman
shaunhartman.com › articles › using-javascript-sets
Using Sets for Efficient Filtering in JavaScript - Shaun Hartman
The Set() doesn't have a .length property like a primitive array, but instead has .size property to check the number of element inside set and .add() method to add new element. Furthermore, we were also able to combine multiple filters to create a more specific set of data.
GeeksforGeeks
geeksforgeeks.org › how-to-map-reduce-and-filter-a-set-element-using-javascript
How to map, reduce and filter a Set element using JavaScript ? | GeeksforGeeks
February 21, 2023 - To get the difference between two sets in JavaScript, you need to identify elements present in the first set but not in the second. This involves iterating over the first set and filtering out elements that are also found in the second set, ensuring efficient comparison.
W3Schools
w3schools.com › jsref › jsref_filter.asp
JavaScript Array filter() Method
cssText getPropertyPriority() getPropertyValue() item() length parentRule removeProperty() setProperty() JS Conversion · ❮ Previous JavaScript Array Reference Next ❯ · Return an array of all values in ages[] that are 18 or over: const ages = [32, 33, 16, 40]; const result = ages.filter(checkAdult); function checkAdult(age) { return age >= 18; } Try it Yourself » ·
MDN Web Docs
developer.mozilla.org › en-US › docs › Web › JavaScript › Reference › Global_Objects › Array › filter
Array.prototype.filter() - JavaScript - MDN Web Docs
September 2, 2026 - The filter() method of Array instances creates a shallow copy of a portion of a given array, filtered down to just the elements from the given array that pass the test implemented by the provided function.
Medium
medium.com › poka-techblog › simplify-your-javascript-use-map-reduce-and-filter-bd02c593cc2d
Simplify your JavaScript – Use .map(), .reduce(), and .filter() | by Etienne Talbot | poka-techblog | Medium
September 4, 2019 - What if you have an array, but only want some of the elements in it? That’s where .filter() comes in!
Mimo
mimo.org › glossary › javascript › filter
Master JavaScript Filter Operator: Apply Filter Arrays
The JavaScript filter() method creates a new array with all elements that pass the test implemented by the provided function.
Medium
medium.com › @benjamin.flanders96 › how-to-create-a-simple-javascript-filter-67e50b32ccb5
How to Create A Simple JavaScript Filter | Medium
July 22, 2020 - The goal for any good filter should be to empower the user to find the exact information they need. There are SEVERAL different ways to get this done depending on the parameters of your project, but today we are going to look at a very simple and easy way to achieve this filtration with JavaScript and CSS class names. The first thing we need to do is set ...
GeeksforGeeks
geeksforgeeks.org › javascript › how-to-map-reduce-and-filter-a-set-element-using-javascript
High-Order Array Methods - GeeksforGeeks
July 30, 2025 - arr = new Array(1, 2, 3, 6, 5, 4); var new_arr = arr.filter(function (x){ return x % 2==0; }); console.log(new_arr)
Built In
builtin.com › software-engineering-perspectives › javascript-filter
How to Filter a JavaScript Array With the Filter() Method | Built In
Javascript filter() method always returns a new array, it does not modify the original array. Arrow functions provide a concise syntax for defining callback functions. It makes the code easier to read and write. Use the second argument. The filter() method has an optional second argument that can be used to set the value of this within the callback function.
BitDegree
bitdegree.org › learn › javascript-filter
JavaScript Filter: Guide on Filtering Arrays and Creating New Ones
February 25, 2020 - TL;DR – JavaScript filter() function is for defining a new array with elements from the initial array that match a specified condition/function.
YouTube
youtube.com › watch
How to Use filter() in JavaScript | Filter Arrays Like a Pro - YouTube
🔍 Master the JavaScript filter() Method | Filter Arrays with Ease and Efficiency (2025)The filter() method is a crucial JavaScript tool that lets you create...
Published: June 15, 2025
freeCodeCamp
freecodecamp.org › news › javascript-filter-method
How the JavaScript Filter Method Works – Explained with Code Examples
February 15, 2024 - The filter method in JavaScript is designed as a higher-order function that iterates over each element of an array, allowing developers to apply a specific condition to filter out elements.
AG Grid
ag-grid.com › javascript-data-grid › filter-set-filter-list
JavaScript Grid: Set Filter - Filter List | AG Grid
Note that the Cell Component will be supplied additional info when used to format cells inside the grid (as grid cells have row details that are not present for values inside a Filter List). Assuming you have a custom Country Cell Component, the following snippet shows how to provide the countryCellRenderer to the Set Filter:
AG Grid
ag-grid.com › javascript-data-grid › filter-set-mini-filter
JavaScript Grid: Set Filter - Mini Filter | AG Grid
When the ↵ Enter key is pressed while on the Mini Filter, the Set Filter will exclusively select all values in the Filter List that pass the Mini Filter and apply the filter immediately (note that even if an Apply Button is used, hitting ↵ Enter applies the filter).
Ultimate Courses
ultimatecourses.com › blog › array-filter-javascript
Exploring Array Filter in JavaScript - Ultimate Courses
Follow along with the Exploring JavaScript Array Methods series! ... Array Filter is a method that exists on the Array.prototype that was introduced in ECMAScript 5 (ES5) and is supported in all modern browsers.
W3Schools
w3schools.com › jsref › prop_style_filter.asp
HTML DOM Style filter Property
Note: The filters that use percentage values (i.e. 75%), also accept the value as decimal (i.e. 0.75). ... Coding fundamentals as bite-sized lessons and challenges. ... If you want to use W3Schools services as an educational institution, team or enterprise, send us an e-mail: sales@w3schools.com · If you want to report an error, or if you want to make a suggestion, send us an e-mail: help@w3schools.com · HTML Tutorial CSS Tutorial JavaScript Tutorial How To Tutorial SQL Tutorial Python Tutorial W3.CSS Tutorial Bootstrap Tutorial PHP Tutorial Java Tutorial C++ Tutorial jQuery Tutorial
MDN Web Docs
developer.mozilla.org › en-US › docs › Web › JavaScript › Reference › Global_Objects › Set
Set - JavaScript - MDN Web Docs
August 13, 2026 - Set objects are collections of values. A value in the set may only occur once; it is unique in the set's collection. You can iterate through the elements of a set in insertion order.