Delete duplicate elements from an array [duplicate]

Answer 1

As elements are yet ordered, you don't have to build a map, there's a fast solution :

var newarr = [arr[0]];
for (var i=1; i

If your array weren't sorted, you would use a map :

var newarr = (function(arr){
  var m = {}, newarr = []
  for (var i=0; i

Note that this is, by far, much faster than the accepted answer.