What is the dollar sign in Javascript, if not jQuery
It means nothing to the interpreter just like the underscore
From the ECMAScript specification:
The dollar sign ($) and the underscore (_) are permitted anywhere in an identifier. The dollar sign is intended for use only in mechanically generated code.
You may also check JavaScript Dollar Sign ($) - What is it for?
By convention, the dollar sign ($), the underscore (_) and even some ASCII character are permitted to be used anywhere in a JavaScript identifier (Source: Ecma Script documentation (7.6 Identifiers, ECMA-262, 3rd Ed.) the dollar sign is intended for use only in mechanically generated code. This means that we do not want to use the dollar sign ($) in our indentifier names, unless we are writing a framework. The following is a list of permitted characters that can be used anywhere in an identifier name:
IdentifierName ::
IdentifierStart
IdentifierName IdentifierPart
IdentifierStart ::
UnicodeLetter
$
_
UnicodeEscapeSequence
IdentifierPart ::
IdentifierStart
UnicodeCombiningMark
UnicodeDigit
UnicodeConnectorPunctuation
UnicodeEscapeSequence
EDIT:-
Actually dollar sign function has become the more-or-less de facto shortcut to document.getElementById()
.
To confirm my point check this:
$(selector)
Returns a single element matching the given CSS selector. In old Firebug versions, this used to be equivalent to document.getElementById.
1) Is it correct that dollar sign was not assigned, a few years back, or do I remember wrong?
That's correct and still true.
2) What is the dollar sign, if not jQuery?
Firefox and Chrome implement $
, $$
and several others as helper commands. Both will set $$
to document.querySelectorAll()
, and set $
to document.querySelector
if window.$
hasn't been defined.
So what you're seeing isn't actually standard JavaScript, but a helper in the developer console of your browser. It's also not jQuery (as long as you're not on a page using jQuery). However, it's behaviour is close to the one of jQuery
, concerning that querySelector
(for single matches) and querySelectorAll
(for multiple matches) give you almost the same strength as the jQuery selector.