更新时间:2023-02-19 23:07:33
$()
返回基于选择器的元素集合.所以$('.help')
将返回所有具有.help
类的元素.$('.help')[0]
会给你第一个元素.
$()
returns a collection of elements based on the selector. So $('.help')
would return all elements with a class of .help
. $('.help')[0]
would give you the first element.