andrew310 · August 3, 2016 21:52
diff --git a/dedupe.js b/dedupe.js
 var list = [1, 4, 8, 33, 2, 1, 5, 7, 8, 6, 3, 2];

 /*VERSION 1 */
 //retains current order of the list
 var dups = {}; //create an object, purpose is we want keys

 var uniques = list.filter(function(item){
  return dups.hasOwnProperty(item) ? false : dups[item] = true;
 });
 /* How does this work?
 /  So we are using javascript objects as maps here. As you go through the list, the filter function passes the callback function each item
 /  in the list to see if it should retain that item in the filtered list. If the item is not in the dups map, we add that key to the dups
 /  map (dups[item] = true) and then return true so that this item will be retained in the list.
 /  if the key is found in the dups map, the callback function returns false, and this current item is tossed from the list.
 */

 /*VERSION 2*/
 //does NOT retain current order. This is basically the same as the ES6 "set" function, also in Python.
 var sortedUniques = list.sort(function(a, b){return a-b;}).filter(function(item, pos, arr){
  return !pos || item != arr[pos - 1];
 })
 /* How does it work?
 /  the filter function basically checks if the current item is the same as the one before it. (This works because it is sorted).
 /  if it is the same, it is tossed from the list. If not, it returns true because of the or statement, so it is retained.
 /*
	var list = [1, 4, 8, 33, 2, 1, 5, 7, 8, 6, 3, 2];

	/VERSION 1 /
	//retains current order of the list
	var dups = {}; //create an object, purpose is we want keys

	var uniques = list.filter(function(item){
	return dups.hasOwnProperty(item) ? false : dups[item] = true;
	});
	/* How does this work?
	/ So we are using javascript objects as maps here. As you go through the list, the filter function passes the callback function each item
	/ in the list to see if it should retain that item in the filtered list. If the item is not in the dups map, we add that key to the dups
	/ map (dups[item] = true) and then return true so that this item will be retained in the list.
	/ if the key is found in the dups map, the callback function returns false, and this current item is tossed from the list.
	*/

	/VERSION 2/
	//does NOT retain current order. This is basically the same as the ES6 "set" function, also in Python.
	var sortedUniques = list.sort(function(a, b){return a-b;}).filter(function(item, pos, arr){
	return !pos \|\| item != arr[pos - 1];
	})
	/* How does it work?
	/ the filter function basically checks if the current item is the same as the one before it. (This works because it is sorted).
	/ if it is the same, it is tossed from the list. If not, it returns true because of the or statement, so it is retained.
	/*