add Medium_151_Reverse_Words_in_a_String

Author: zongyanqi

Medium_151_Reverse_Words_in_a_String.js

@@ -0,0 +1,18 @@
+/**
+ * Given an input string, reverse the string word by word.
+
+ For example,
+ Given s = "the sky is blue",
+ return "blue is sky the".
+ */
+
+/**
+ * @param {string} str
+ * @returns {string}
+ */
+var reverseWords = function (str) {
+    return str.split(' ')
+              .filter(w => w)
+              .reverse()
+              .join(' ');
+};