Removing An Element

Part of the Logic & Flow section of Coddy's JavaScript journey — lesson 31 of 65.

To remove an element from a Set, use the delete() method. This method removes the specified element from the Set if it exists. If the element doesn't exist, the Set remains unchanged.

Here's how to use the delete() method:

const mySet = new Set([1, 2, 3, 4, 5]);

mySet.delete(3);
console.log(mySet); // Set(4) { 1, 2, 4, 5 }

// Trying to delete a non-existent element
mySet.delete(10);
console.log(mySet); // Set(4) { 1, 2, 4, 5 } (unchanged)

The delete() method returns a boolean indicating whether the element was successfully removed:

console.log(mySet.delete(2)); // true
console.log(mySet.delete(10)); // false

Challenge

Easy

Create a function called removeMultiples that takes two parameters: an array of numbers and a number n. The function should convert the array to a set, and remove all multiples of n from the Set (including n itself if it's in the Set). Finally convert the set to an array and return it.

Multiples are the numbers you get when you multiply a given number (n) by all whole numbers (1, 2, 3, etc.).

For example, if n = 3:

The multiples of 3 are: 3, 6, 9, 12, 15, 18, 21, 24, and so on...

Cheat sheet

To remove an element from a Set, use the delete() method:

const mySet = new Set([1, 2, 3, 4, 5]);

mySet.delete(3);
console.log(mySet); // Set(4) { 1, 2, 4, 5 }

The delete() method returns a boolean indicating whether the element was successfully removed:

console.log(mySet.delete(2)); // true (element existed and was removed)
console.log(mySet.delete(10)); // false (element didn't exist)

If the element doesn't exist in the Set, it remains unchanged and delete() returns false.

Try it yourself

function removeMultiples(arr, n) {
  // Write your code here
}

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

All lessons in Logic & Flow

1Strings In Depth

String Fundamentals Iterate Over Strings Template Literals String Methods Recap - String Weaver

4JSON Part 2

Iterate Over JSON Nested JSON JSON Optional Chaining Shallow And Deep Copy Recap - Bicycle Shop Recap - Solar System

7Library Management System

Project Overview Adding Books

Search By Title

Filter By Genre

Mark As Read

10Manage Festival System

Project Overview Add Movies & Venues

2Multi-dimensional Arrays

2D Arrays Basics Accessing 2D Array Elements Nested Loops with 2D Arrays Recap - 2D Arrays Matrix Addition & Substraction Jagged Arrays 3D Arrays And Beyond Common 2D Array Patterns Recap - All About Arrays

5Sets Part 1

What Is A Set?Iterating Over Sets Adding An ElementRemoving An ElementChecking If An Element Exists Size And Is Empty Copy And Clear Recap - Basic Of Sets

8Arrays Interesting Topics

Array Destructuring Spread Syntax in Arrays Sparse Arrays Recap - Arrays Workshop