uniq

Removes all duplicates from an array in place.

Usage

First install using npm:

npm install uniq

Then use it as follows:

 
var arr = [1, 1, 2, 2, 3, 5]
 
require("uniq")(arr)
console.log(arr)
 
//Prints: 
// 
//  1,2,3,5 
//

Removes all duplicates from a sorted array in place.

array is the array to remove items from
compare is an optional comparison function that returns 0 when two items are equal, and something non-zero when they are different. If unspecified, then the default equals will be used.
sorted if true, then assume array is already sorted

Returns: A reference to array

Time Complexity: O(array.length * log(arra.length)) or O(array.length) if sorted

A few reasons:

This library updates the array in place without making an extra copy (and so it is faster for large arrays)
It also accepts a custom comparison function so you can remove duplicates from arrays containing object
It is more modular in the sense that it doesn't come with a bazillion other utility grab bag functions.