$（'。classname'）和$ .find（'。classname'）之间有什么区别

Question

Sometimes $('.classname') and $.find('.classname') gives different result. Wondering what is the difference between both.

Answer 1

$('.classname')

will search the DOM for elements with class classname and

$.find('.classname')

will give you error do nothing, why

.find( selector )

selectorA string containing a selector expression to match elements against. version added: 1.6.

.find( jQuery object ) jQuery objectA jQuery object to match elements against. version added: 1.6

.find( element ) elementAn element to match elements against.

Answer 2

I can't tell you,

but you can see the source-code for $.find and for $.fn.find

$.find :

It's a method used by jQuery itself and not recomented to use as query selector.

$.fn.find :

Refers to $.find in the core framework: (where this is a jQuery Object)

var ret = this.pushStack("", "find", selector),
    length, n, r;

for (i = 0, l = this.length; i < l; i++) {
    length = ret.length;
    jQuery.find(selector, this[i], ret);

    ...

Answer 3

$('.classname') will return a list of all of the elements with that classname in the document so they can be iterated with .each() .

$.find('.classname') searches the dom tree and returns occurances of the class. But you would have to supply a parent element, eg:

$(document).find('.classname')