add hw2

node_modules/lodash-es/pickBy.js

@@ -0,0 +1,37 @@
+import arrayMap from './_arrayMap.js';
+import baseIteratee from './_baseIteratee.js';
+import basePickBy from './_basePickBy.js';
+import getAllKeysIn from './_getAllKeysIn.js';
+
+/**
+ * Creates an object composed of the `object` properties `predicate` returns
+ * truthy for. The predicate is invoked with two arguments: (value, key).
+ *
+ * @static
+ * @memberOf _
+ * @since 4.0.0
+ * @category Object
+ * @param {Object} object The source object.
+ * @param {Function} [predicate=_.identity] The function invoked per property.
+ * @returns {Object} Returns the new object.
+ * @example
+ *
+ * var object = { 'a': 1, 'b': '2', 'c': 3 };
+ *
+ * _.pickBy(object, _.isNumber);
+ * // => { 'a': 1, 'c': 3 }
+ */
+function pickBy(object, predicate) {
+  if (object == null) {
+    return {};
+  }
+  var props = arrayMap(getAllKeysIn(object), function(prop) {
+    return [prop];
+  });
+  predicate = baseIteratee(predicate);
+  return basePickBy(object, props, function(value, path) {
+    return predicate(value, path[0]);
+  });
+}
+
+export default pickBy;