update snippets 1-15

snippets/arrayGcd.md

@@ -9,6 +9,9 @@ const arrayGcd = arr =>{
   const gcd = (x, y) => !y ? x : gcd(y, x % y);
   return arr.reduce((a,b) => gcd(a,b));
 }
-// arrayGcd([1,2,3,4,5]) -> 1
-// arrayGcd([4,8,12]) -> 4
+```
+
+```js
+arrayGcd([1,2,3,4,5]) -> 1
+arrayGcd([4,8,12]) -> 4
 ```