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by hamxiaoz 4472 days ago
What does the $$ mean?
2 comments

Looking at it in the console, it looks like $ returns a single DOM element and $$ returns a NodeList (array-like object) of DOM elements. Not sure what library that is.
No library, at least in Firefox it's defined by devtools and only works in the console (provided the page doesn't have it's own $ and $$ globals).

[0] http://dxr.mozilla.org/mozilla-central/source/toolkit/devtoo...

[1] http://dxr.mozilla.org/mozilla-central/source/toolkit/devtoo...

Edit: It works in the WebKit devtools too:

[0] https://mxr.mozilla.org/chromium/source/src/third_party/WebK...

PrototypeJS works that way.
It's shorthand for document.querySelectorAll: https://developers.google.com/chrome-developer-tools/docs/co...