From a4c1f68717c74d63dca87561d0228fe8dd64a768 Mon Sep 17 00:00:00 2001
From: spassaro80 <43064539+spassaro80@users.noreply.github.com>
Date: Thu, 22 Aug 2019 19:40:06 +0200
Subject: [PATCH] Solution using RegExp (#36665)
* Update index.md
I think it can be interesting to propose a solution using RegExp.
* fix: wrapped code in code fences
---
.../mutations/index.md | 31 ++++++++++++++++++-
1 file changed, 30 insertions(+), 1 deletion(-)
diff --git a/guide/english/certifications/javascript-algorithms-and-data-structures/basic-algorithm-scripting/mutations/index.md b/guide/english/certifications/javascript-algorithms-and-data-structures/basic-algorithm-scripting/mutations/index.md
index ef89c65dec..f85d80ccd8 100644
--- a/guide/english/certifications/javascript-algorithms-and-data-structures/basic-algorithm-scripting/mutations/index.md
+++ b/guide/english/certifications/javascript-algorithms-and-data-structures/basic-algorithm-scripting/mutations/index.md
@@ -90,4 +90,33 @@ Grab the second string, lowercase and turn it into an array; then make sure _eve
* Array.split()
* Array.every()
-
\ No newline at end of file
+
+
+
+Solution 3 (Click to Show/Hide)
+
+**Declarative**
+
+```js
+function mutation(arr) {
+ for (var el of arr[1]){
+ let re = new RegExp(el,"i");
+ if (re.test(arr[0]) == false){
+ return false;
+ }
+ }
+ return true;
+}
+```
+
+#### Code Explanation
+
+* For every letter of the second Array we want to check if it's in the first array using the test() Method.
+* The RegExp(el,"i") function will create a Regular Expression for every letter. For example RegExp("Hey",i) will create /H/i, then /e/i, then /y/i.
+* If there is one letter that return false, than we return false. If arr[0] contains all letters than we return true.
+
+#### Relevant Links
+
+* RegExp.test()
+
+