update snippets 62-78

snippets/intersection.md

@@ -6,5 +6,8 @@ Create a `Set` from `b`, then use `Array.filter()` on `a` to only keep values co
 
 ```js
 const intersection = (a, b) => { const s = new Set(b); return a.filter(x => s.has(x)); };
-// intersection([1,2,3], [4,3,2]) -> [2,3]
+```
+
+```js
+intersection([1,2,3], [4,3,2]) -> [2,3]
 ```