problems(js): add “2634. Filter Elements from Array”

Signed-off-by: Matej Focko <mfocko@redhat.com>

problems/filter-elements-from-array.js

@@ -0,0 +1,17 @@
+/**
+ * @param {number[]} arr
+ * @param {Function} fn
+ * @return {number[]}
+ */
+var filter = function(arr, fn) {
+    let new_arr = new Array();
+
+    let i = 0;
+    for (let x of arr) {
+        if (fn(x, i++)) {
+            new_arr.push(x);
+        }
+    }
+
+    return new_arr;
+};