How does JQuery use $?

[retro-starr]

Isn't JQuery just a javascript file with some nice functions pre-made for you, so how does it use $?

[Synook]

$ is a valid symbol name in JavaScript. Try it!

$ = "blah blah";alert($); // alerts "blah blah"

So the jQuery script just assigns a whole lot of stuff to the variable called $.

[boen_robot]

For the record, your definition of jQuery is spot on. A file with nice stuff pre-made for you is what's generally reffered to as a "library". In jQuery's case, that would be a JavaScript library, since the pre-made stuff is JavaScript functions. In, for example, a PHP context, a library could consist of a collection of nice PHP classes, functions and/or constants.A portion or a superset of such a collection that's used for a specific purpose is usually reffered to as API. A library and an API will sometimes overlap. e.g. the GD library in C is exposed to PHP via PHP's GD API. In this case we call PHP's part "API" because it's only an "interface" (a bridge if you will) to the real deal.

[retro-starr]

I thought

[variable] names must begin with a letter or the underscore character

. Is w3schools just giving the best practices for variables or is this really the case? Cause if it is, would browsers just be overlooking this mistake?

[jeffman]

Somehow $ fell through the cracks. All other non-alphanumeric characters on a US keyboard serve a programming purpose of some kind, so they would be misunderstood as variable identifiers.For what it's worth, some popular "evangelists" recommend not using _ at the start of an identifier. It is still technically correct, however.

[retro-starr]

Would it be good or OK to have bash style variables (i.e. $HOME)? Would blur the lines between many languages.

[boen_robot]

It's syntanctically valid, but is not considered good practice exactly because of that blur.

[retro-starr]

That sucks, I thought it'd be the other way around.

[thescientist]

you could also refer the jQuery $ as jQuery too, i.e.

jQuery(document).ready(function(){  //stuff});

[retro-starr]

Is that case-sensitive? I read you could set the variable to use with "var NAME=$.noConflict();".