Let me explain with an example of Jquery. If you ever wish to run Jquery on Console just go to jquery.com and open Console and boom. You have your free Jquery playground available to you.
Let me illustrate it with another example, I will simply get the elements with the id menu-top using the Jquery syntax and magic, it works.
This trick is available in a lot of other libraries like lodash, underscore, Ramda and even in ReactJS too further this might be there in your favorite library also. Let me know other cool libraries where we can do this.
Made with ❤ at Earth.