Your code snippet features only two variables, both are named. One is named "e", the other is named "child". Variables by definition always have a name (more specifically: an identifier). There are no unnamed variables (unless one would consider an indexed storage location/position in a collection or set as a variable).

Assuming unnamed variables were possible, the name of an unnamed variable would be "" (empty string). They would be practically invisible in the source code. Now, wouldn't it be fun if we could sprinkle invisible variables all around our source codes? ;-)

elgonzo‭ what mislead me is the lack on = right after const.

I am just not used to declare variables this way and never had any need of using for...of before.

There's no = after const in any variable declaration. You either declare it as const variableName; or const variableName = someValue; (the = is after the variable name, not after const - yes, that was pedantic from my part, sorry)

Anyway, this for..of code is equivalent to:

for (var i = 0; i < e.childNodes.length; i++) {
    const child = e.childNodes[i];
    // do stuff
}

The for..of just have a different syntax, as the variable is declared inside the parenthesis. But the variable is not unnamed

Additionally to what @hkotsubo wrote, = (assignment) would not be entirely correct here. (It would have been possible to design the language to allow =, but it would make this operator essentially somewhat ambiguous in its use.)

for (const e of {some enumeration} ) is iterating over an enumeration of values/objects, with each iteration the next value/object being assigned to "e".

However, a syntax like for (const e = {some enumeration} ) lends itself to the suggestion that the enumeration itself is being assigned to "e". Which is of course not what the for statement does, so it is better for both readability and reduced risks of making coding errors to use a different operator keyword of instead of overloading the = operator with similar yet different semantics/meanings. (A pet peeve of mine: languages with an == operator which also allow assignment expressions, which is always good for a lot of fun when making a typo wrt to = vs. == in an expression)

hkotsubo‭

I find the for syntax less confusing than for...of syntax, which for me kind of breaks the "regular" flow of almost any elementary/basic JavaScript code I ever worked with.

The purpose of for..of is not only to provide a different syntax. With this statement, you can loop through any iterable object (you can even create your own). Some objects, for instance, don't have the length property or don't support the [ ] syntax to get a specific element, so using for..of is a much straightforward (and standard) way to traverse them. Check the docs for more use cases.

But anyway, that's beside the point. The answer to your question is "yes" - that's the syntax of for..of statement, so the variable must not have the assignment operator. Regarding "why?", it's because the people who defined it decided it that way :-)

elgonzo‭ through the years I wrote a few JavaScript codes which just work so It's not that I don't understand all JavaScript fundamentals, rather, I don't understand some or most as user @r~~ pointed out and I agree with him. I should learn everything I don't know. I wish I should reply to you differently at start.

I have already asked the mods to delete my account.