Another update from ingydotnet^djgoku

Task/Remove-duplicate-elements/JavaScript/remove-duplicate-elements-3.js

@@ -0,0 +1,3 @@
+Array.prototype.unique = function() {
+   return this.sort().reduce( (a,e) => e === a[a.length-1] ? a : (a.push(e), a), [] )
+}

Task/Remove-duplicate-elements/JavaScript/remove-duplicate-elements-4.js

@@ -0,0 +1,3 @@
+Array.prototype.unique = function() {
+    return [... new Set(this)]
+}

Task/Remove-duplicate-elements/JavaScript/remove-duplicate-elements-5.js

@@ -0,0 +1,15 @@
+function uniq(lst) {
+  var u = [],
+    dct = {},
+    i = lst.length,
+    v;
+
+  while (i--) {
+    v = lst[i], dct[v] || (
+      dct[v] = u.push(v)
+    );
+  }
+  u.sort(); // optional
+
+  return u;
+}