add pick code snippiet

snippets/pick.md

@@ -0,0 +1,23 @@
+### Pick
+
+Use `Objexts.keys()` to convert given object to an iterable arr of keys.
+Use `.filter()` to filter the given arr of keys to the expected arr of picked keys.
+Use `.reduce()` to convert the filtered/picked keys back to a object with the corresponding key:value pair.
+
+```js
+const pick = (obj, arr) =>
+  Object
+    .keys(obj)
+    .filter((v, i) => arr.indexOf(v) !== -1 )
+    .reduce((acc, cur, i) => {
+      acc[cur] = obj[cur];
+      return acc;
+    }, {});
+
+// const object = { 'a': 1, 'b': '2', 'c': 3 };
+// pick(object, ['a', 'c']) -> { 'a': 1, 'c': 3 }
+
+// pick(object, ['a', 'c'])['a'] -> 1
+// pick(object, ['a', 'c'])['c'] -> 3
+
+```