Get all unique/distinct values in a JavaScript array

To remove duplicates and get unique values from an array, we can use the »Set()« class, which creates a representation of the array with unique values from the existing array.

Let’s take the following list of names as an example. Janet is a duplicate in there.

const list = [
  'George',
  'Janet',
  'Emma',
  'Eve',
  'Charles',
  'Janet',
  'Tracey',
];

Using Set, we can convert that array to a Set object that stores unique values.

const unique = new Set(list);

As you can see, the duplicate Janet is removed.

However, the Set object is no array and thus usual array methods such as .forEach() or .map() won’t work. To fix this, you can convert the set back to an array by generating a new array based on the set using Array.from().

const unique = Array.from(new Set(list));

Of course, you can also use the spread operator.

const unique = [...new Set(list)];

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