问题
I've noticed that there appears to be a global function called $ in some browsers which is NOT jQuery, but I can't seem to find any documentation on it. What is it?
Firefox:
Chrome:
回答1:
Chrome and Firefox dev tools include some useful shortcuts/helpers to manipulate the DOM within the console.
These shortcuts are pretty similar for both: $ for DOM selection, $0-$4 for "last X selections" and more.
For full reference see:
- Chrome Dev Tools Command Line API - https://developers.google.com/web/tools/chrome-devtools/console/command-line-reference
- Firefox Web Console Helpers - https://developer.mozilla.org/en-US/docs/Tools/Web_Console/Helpers
回答2:
There is no global $ in browsers.
Some browsers provide a $ in the scope of the Console (if there isn't a global one already).
For example Chrome's documentation says:
$(selector) returns the reference to the first DOM element with the specified CSS selector. This function is an alias for the document.querySelector() function.
来源：https://stackoverflow.com/questions/53554987/browser-default-global-function