Search methods in JavaScript

There are two Search methods in JavaScript i’ve found, out of the four, Includes and IndexOf(), also it would be good to focus on Node.Js as a backend framework in the future (with Flask for Python). The code below, IndexOf() uses a while loop for a string with characters in it, and the array.includes searches an array with the int specified parentheses. GitHub links below to both separate programs.

IndexOf() : https://github.com/jamie082/search_js_indexOf

Includes version: https://github.com/jamie082/search_array_js