Delete duplicate elements from an array

For example, I have an array like this;

var arr = [1, 2, 2, 3, 4, 5, 5, 5, 6, 7, 7, 8, 9, 10, 10]

My purpose is to discard repeating elements from array and get final array like this;

var arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

How can this be achieved in JavaScript?

NOTE: array is not sorted, values can be arbitrary order.