Input vs :Input in jQuery

问题:

I wonder why people seems to prefer :input over input as a jQuery selector? Basically, this two lines seem to do the same thing :

$('input:first').focus()
$(':input:first').focus()

But second version is more widely use, and I don't find why. Moreover, the :input selector seem slower according to this benchmark: http://jsperf.com/input-vs-input/2

回答1:

:input is pseudo selector by jQuery which includes <buttons>, <textarea>, e.t.c

input is a tag match which strictly matches <input>.

This additional note about :input is informative:

Because :input is a jQuery extension and not part of the CSS specification, queries using :input cannot take advantage of the performance boost provided by the native DOM querySelectorAll() method. To achieve the best performance when using :input to select elements, first select the elements using a pure CSS selector, then use .filter(":input").

--from https://api.jquery.com/input-selector/

回答2:

input is just the input element selector. :input also selects textarea, select, and button (form controls).

It's not necessarily a matter of preference since in actuality they do somewhat different things.

回答3:

:input selects all input, textarea, select and button elements, while input just selects elements with an input tag.