While Set API is still very minimalistic, you can use Array.prototype.forEach and shorten your code a bit:
array.forEach(item => mySet.add(item))
// alternative, without anonymous arrow function
array.forEach(mySet.add, mySet)
Top answer 1 of 12
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While Set API is still very minimalistic, you can use Array.prototype.forEach and shorten your code a bit:
array.forEach(item => mySet.add(item))
// alternative, without anonymous arrow function
array.forEach(mySet.add, mySet)
2 of 12
137
Here's a functional way, returning a new set:
const set = new Set(['a', 'b', 'c'])
const arr = ['d', 'e', 'f']
const extendedSet = new Set([ ...set, ...arr ])
// Set { 'a', 'b', 'c', 'd', 'e', 'f' }
JSchallenger
jschallenger.com › javascript-practice › javascript-sets › add-multiple-elements-to-javascript-set
Add multiple elements to Set | JSchallenger
JSchallenger. Write a function that takes a Set and an array as arguments. If not already existing, add each element in the array to the Set. Return the modified Set
How to give an object property multiple values in js
You need to define each level. You can't do this: let obj = {}; obj.bla.a = 3; It will tell you that obj.bla is not defined. Rather, you have to define the bla property first, and then you can add sub-properties to it. Like so: let obj = {}; obj.bla = {}; obj.bla.a = 3; Good luck learning js, its been fun last couple of months for me! More on reddit.com
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April 8, 2018Setinterval() going crazy. Can't figure it out!
Move your line 15,
var tweetcounter;
Out of the function. clearInterval runs against undefined, then you assign it, then it goes out of scope.
Or do what u/uazaa says and make it a setTimeout instead.
More on reddit.com 6
1
February 24, 2016Help with multiple lined innerHTML assignment
and i want to continue on line 2 </p> was supposed to be on the next line
More on reddit.com 8
5
March 28, 2014How to append multiple classes to an element? JavaScript DOM
Use classList instead of setAttribute. setAttribute should be avoided for setting classes, as it will overwrite whatever is already set, making adding classes overly complicated. Also, avoid making multiple appends to your DOM whenever possible. Build up the section element, appending all of its child elements, then append the section element to your "workspace." Also also, the code you have written does not match the HTML. You are appending the city div outside the section, instead of nested in an H2 element. More on reddit.com
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October 10, 202004:55
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MDN Web Docs
developer.mozilla.org › en-US › docs › Web › JavaScript › Reference › Global_Objects › Set › add
Set.prototype.add() - JavaScript - MDN Web Docs - Mozilla
const mySet = new Set(); mySet.add(1); mySet.add(5).add("some text"); // chainable console.log(mySet); // Set [1, 5, "some text"]
W3Schools
w3schools.com › js › js_sets.asp
JavaScript Sets
A JavaScript Set is a collection of unique values. Each value can only occur once in a Set. The values can be of any type, primitive values or objects. ... // Create a Set const letters = new Set(); // Add Values to the Set letters.add("a"); letters.add("b"); letters.add("c"); Try it Yourself »
GeeksforGeeks
geeksforgeeks.org › javascript › javascript-set-add-method
JavaScript Set add() Method - GeeksforGeeks
June 4, 2026 - ... // Create a new set using Set() constructor let myset = new Set(); // Append new elements to the set // using add() method with chaining myset.add(23).add(12); // Appending an already existing // element to the set this // element will not ...
EyeHunts
tutorial.eyehunts.com › home › javascript set add multiple | example
JavaScript Set add multiple | Example - Tutorial - By EyeHunts
August 11, 2022 - const arr = [1, 2, 3, 3, 4]; const existingSet = new Set(); for (const item of arr) { existingSet.add(item); }
Medium
medium.com › @conboys111 › what-happens-when-you-add-objects-or-arrays-to-a-javascript-set-b9f15dbbc5e0
What Happens When You Add Objects or Arrays to a JavaScript Set? | by myHotTake | Medium
November 11, 2024 - They both have the same type and name, but because they are two different objects in memory, the Set treats them as two unique dragons. This is because JavaScript objects are compared by reference, not by their content (value). Now, what happens if someone tries to add the same exact dragon twice?
Designcise
designcise.com › web › tutorial › how-to-add-array-values-to-an-existing-javascript-set
How to Add Array Values to an Existing JavaScript Set? - Designcise
September 27, 2021 - // ES6+ const arr = [1, 2, 3, 3, 4]; const existingSet = new Set(); existingSet.add(1); existingSet.add(2); existingSet.add(5); arr.forEach((item) => existingSet.add(item)); console.log(existingSet); // Set(5) { 1, 2, 5, 3, 4 }
Alex Devero Blog
blog.alexdevero.com › home › introduction to sets in javascript – all you need to know
Introduction to Sets in JavaScript - All You Need to Know
August 17, 2020 - The second option is to add values right at moment you are creating a set. To do this, you have to pass an iterable with some values as a parameter to set constructor. Remember that it is necessary to pass those values as iterable, that is an array.
GeeksforGeeks
geeksforgeeks.org › javascript › javascript-insert-multiple-elements-in-js-array
JavaScript - Insert Multiple Elements in JS Array - GeeksforGeeks
July 23, 2025 - This method creates a new array to insert elements. The JavaScript spread syntax (...) can be used to add multiple elements in the JS array.
Telerik
telerik.com › blogs › understanding-utilizing-javascript-set-object
Understanding and Utilizing the JavaScript Set Object
February 2, 2024 - A Set object in JavaScript is a collection of unique values, where each value can only occur once within the set. It provides an efficient way to store, retrieve and manipulate distinct values without worrying about duplicates.
freeCodeCamp
freecodecamp.org › news › how-to-use-javascript-collections-map-and-set
How to Use JavaScript Collections – Map and Set
October 5, 2020 - Please note, if you use the same key to add a value to a Map multiple times, it'll always replace the previous value: // Add a different writer map.set('writer', 'Someone else!'); ... Map keys can be of any type, a primitive, or an object. This is one of the major differences between Map and regular JavaScript objects where the key can only be a string:
ZetCode
zetcode.com › js-array › set
JavaScript set() - working with Sets in JS
We add object references to a Set. Even though obj1 and obj2 have identical properties, they are different objects in memory. Adding the same object reference multiple times only stores it once.
Bobby Hadz
bobbyhadz.com › blog › javascript-set-multiple-attributes-to-element
Set multiple Attributes on an Element using JavaScript | bobbyhadz
Set multiple Attributes on an Element ... using JavaScript · To set multiple attributes at once on an element: Add the attribute names and values to an object....
MDN Web Docs
developer.mozilla.org › en-US › docs › Web › JavaScript › Reference › Global_Objects › TypedArray › set
TypedArray.prototype.set() - JavaScript - MDN Web Docs
July 10, 2025 - The set() method of TypedArray instances stores multiple values in the typed array, reading input values from a specified array.
Quora
quora.com › How-do-I-add-multiple-objects-to-a-single-array-list-in-Javascript
How to add multiple objects to a single array list in Javascript - Quora
Answer (1 of 4): To add multiple objects to a single array , there are two functions you can use : 1. push() : Using this function you can append as many values you want to the array giving one at a time . for eg: var arr=[] [code ]arr.push (2); arr.push (3);[/code] this will result to additio...
GeeksforGeeks
geeksforgeeks.org › javascript-insert-multiple-elements-in-js-array
JavaScript – Insert Multiple Elements in JS Array | GeeksforGeeks
November 15, 2024 - We can insert an item into Array at a specific index using the JavaScript Array splice method. This method removes the elements from the mentioned index and add items at that specific position.1.
MDN Web Docs
developer.mozilla.org › en-US › docs › Web › JavaScript › Reference › Global_Objects › Set › Set
Set() constructor - JavaScript - MDN Web Docs
September 13, 2025 - const mySet = new Set(); mySet.add(1); // Set [ 1 ] mySet.add(5); // Set [ 1, 5 ] mySet.add(5); // Set [ 1, 5 ] mySet.add("some text"); // Set [ 1, 5, 'some text' ] const o = { a: 1, b: 2 }; mySet.add(o);
YouTube
youtube.com › code 2020
JavaScript tips — Add multiple values to an array using Array.push - YouTube
Add multiple values to an array in JavaScript by calling array.push with a list of arguments. This will append the list of arguments to the end of the array ...
Published: October 9, 2022
Views: 3K
CoreUI
coreui.io › answers › how-to-add-to-a-set-in-javascript
How to add to a Set in JavaScript · CoreUI
November 6, 2025 - Use the add() method to insert new values into a Set while maintaining uniqueness automatically.