Apply Functional Programming to Convert Strings to URL Slugs solution…

….md (#8250)

* Update index.md

search for non-word character, split at these points, then using the filter method, filter for extra space, join the dash, and then convert to lower case.

* Update index.md

src/pages/certifications/javascript-algorithms-and-data-structures/functional-programming/apply-functional-programming-to-convert-strings-to-url-slugs/index.md

@@ -3,8 +3,16 @@ title: Apply Functional Programming to Convert Strings to URL Slugs
 ---
 ## Apply Functional Programming to Convert Strings to URL Slugs
 
-This is a stub. <a href='https://github.com/freecodecamp/guides/tree/master/src/pages/certifications/javascript-algorithms-and-data-structures/functional-programming/apply-functional-programming-to-convert-strings-to-url-slugs/index.md' target='_blank' rel='nofollow'>Help our community expand it</a>.
+// the global variable
+var globalTitle = "Winter Is Coming";
 
-<a href='https://github.com/freecodecamp/guides/blob/master/README.md' target='_blank' rel='nofollow'>This quick style guide will help ensure your pull request gets accepted</a>.
+// Add your code below this line
+function urlSlug(title) {
+return title.split(/\W/).filter((obj)=>{
+    return obj !=='';
+  }).join('-').toLowerCase();
+
+}
+// Add your code above this line
 
-<!-- The article goes here, in GitHub-flavored Markdown. Feel free to add YouTube videos, images, and CodePen/JSBin embeds  -->
+var winterComing = urlSlug(globalTitle); // Should be "winter-is-coming"