I'm learning JavaScript, but have had my fingers in code for a while. I've noticed a few different naming conventions, depending on the crowd I collaborate with, though I'm still getting better at naming variables myself. From what I've seen, variable naming conventions have more to do with the language you're using and your goals in writing the software than experience as a programmer.
Older coders, and coders of older languages tend to be more descriptive about the type their variable will represent. I believe this comes from languages where hungarian notation was used, or languages where variables of different types are declared differently. I find this wordy and unnecessary in JavaScript where the types aren't so strict - and it could actually be actively misleading if the variable changes type after it's created!
Another group of people I code with are Code Golfers, people who try to write code to be as small as possible and still run. Their naming conventions usually involve naming all variables in your code single letters, alphabetically, starting at a. This can be pretty confusing when you first look at a piece of code, but it focuses you to be so much more aware of the structure of your code, so I can see why they do it (saving bytes, and help focus on the design)
In my own programming I used to create variable names that were plural too often, I'd use tags instead of tag, or people instead of person, and over time I find using the singular form often reads a lot better later when you're using the variables.
var tags = document.querySelectorAll('div')
for (i in tags) {
tags[i].innerHTML = 'Hello'
}
// vs
var tag = document.querySelectorAll('div')
for (i in tag) {
tag[i].innerHTML = 'Hello'
}
You can see how writing tags makes sense when you're setting the variable - you're looking for multiple tags, but later in the logic it just feels cleaner to work with tag[i] instead of tags[i] when you're modifying a single tag.
I've also seen plenty of variables like isActive or isLoaded which would return either true or false, and phrasing that kind of a variable makes it really nice to write logic like:
if (isActive) { // do stuff }
I still feel like I'm at the start of my programming journey, so I'm looking forward to when I have the insight that comes after making enough mistakes you know which ways are better and which are worse!