The add() method of Set instances inserts the specified value into this set, if it is not already present.

June 4, 2026 - The Set.add() method in JavaScript is used to append an element with a specified value in a set. It modifies the existing set by appending the new element but does not return a new set.

The add() method inserts a new element into a set.

Syntax The clear() method is represented by the following syntax: setObj.clear() JavaScript example Here, we will understand clear() method through various examples. Example 1 Let's see a simple example of clear() method. <script> var set = new Set(); set.add("jQuery"); set.add("AngularJS"); set.add("Bootstrap"); document.writeln("Size before invoking...

You can create a JavaScript Set by: Passing an array to new Set() Create an empty set and use add() to add values · Pass an array to the new Set() constructor: // Create a Set const letters = new Set(["a","b","c"]); Try it Yourself » · Create ...

June 17, 2026 - A JavaScript Set stores unique values. Use the add() method to add a value to a Set.

November 6, 2025 - Use the add() method to insert new values into a Set while maintaining uniqueness automatically.

This method returns the Set object itself with the added values. In the following example, we are using the JavaScript Set.add() method to insert the numbers 5 and 10 to the "numberset" set −

The set.add() function in JavaScript is used to insert an element in the set.

August 13, 2026 - Writeable Set-like objects additionally have the methods: clear(), delete(), and add().

June 16, 2022 - Inserts a value into a Set (if it is unique) and returns the updated Set object.

July 20, 2025 - const set = new Set(); set.add(42); set.add("forty two"); const iterator = set.values(); console.log(iterator.next().value); // Expected output: 42 console.log(iterator.next().value); // Expected output: "forty two"

February 2, 2024 - By leveraging the Set's built-in methods for adding, checking and removing values, developers can simplify their code and reduce the complexity of handling distinct values. Moreover, the Set object ensures uniqueness, maintains insertion order and provides efficient value existence checks, which makes it a powerful tool in specific use cases. A Map object in JavaScript ...

The add() method appends a new element with a specified value to the end of a Set object.

September 22, 2025 - const mySet = new Set(); mySet.add("foo"); console.log(mySet.has("foo")); // true console.log(mySet.has("bar")); // false const set = new Set(); const obj = { key1: 1 }; set.add(obj); console.log(set.has(obj)); // true console.log(set.has({ key1: 1 })); // false, because they are different object references console.log(set.add({ key1: 1 })); // now set contains 2 entries

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 }

June 11, 2024 - There are two primary ways to create sets in JavaScript: ... const mySet = new Set(); // Adding elements mySet.add("John"); mySet.add("Sherlock"); mySet.add("Watson"); mySet.add("Moriarty"); // Duplicate, ignored console.log(mySet); // Output: ...

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);

June 24, 2024 - A set is similar to an Array, except that each value can only be stored once. For example, we can take a list of items, add them all to a set, and then inspect the results of the set. The list on the right is the contents of the <ol> list on the left, but converted to a set.