shouldiprefix VS naming-cheatsheet

That site hasn't been maintained for at least 3 years and the site author is considering archiving it. If that site says No prefixes!" it's safe not to use prefixes. Otherwise, you should look for that information elsewhere.

This guide is my go-to recommendation for freshers for "naming things": https://github.com/kettanaito/naming-cheatsheet

Use better naming. What's variablename? var iab; len(name)? What does reader do? Read a book? https://github.com/kettanaito/naming-cheatsheet

Not an answer, but https://github.com/kettanaito/naming-cheatsheet

But why would you need variable inside a function with the same name? https://github.com/kettanaito/naming-cheatsheet

Use the programming language you're most comfortable with if requirements are not strictly coupled to one programming language. Share your thoughts while you're coding so the interviewers can feel your way of thinking and problem-solving. Also, ask questions when something needs to be clarified for you. Try not to write pieces of code you don't fully understand, for example, using IIFE and not knowing how to pass an argument into it, using ; in front of it, and not knowing why it's used. Try to write readable code with understandable variable and function names. Avoid writing too nested statements, so it's not easy to understand the code's flow. Try to write code that is easy to cover with the tests.

Naming Convention Cheatsheet

Enforce style with a linter. In the js world there is also prettier. Agree upon a naming style for instance this naming cheatsheet although that is harder to enforce

What a great answer :)

Regarding naming things, this comes to my mind: https://github.com/kettanaito/naming-cheatsheet