Removing duplicates from an array in JavaScript can be done in a variety of ways, such as using Array.prototype.reduce()
, Array.prototype.filter()
or even a simple for
loop. But there's an easier alternative. JavaScript's built-in Set
object is described as a collection of values, where each value may occur only once. A Set
object is also iterable, making it easily convertible to an array using the spread (...
) operator.
const nums = [1, 2, 2, 3, 1, 2, 4, 5, 4, 2, 6];
[...new Set(nums)] // [1, 2, 3, 4, 5, 6]
You can wrap this in a helper method, which is exactly what the uniqueElements snippet does. For more complex cases, such as unique objects in an array based on a specific key, you might want to take a look at uniqueElementsBy.
Snippet collection
A collection of quick tips and tricks to level up your coding skills one step at a time.
JavaScript, Array
Creates an object from an array, using a function to map each value to a key.
JavaScript, Array
Maps the values of an array to an object using a function.
JavaScript, Array
Creates an object from an array, using the specified key and excluding it from each value.