jquery - Jquery selecting from variable

Question

I'm very new to jquery and I have an element which I have selected as an object variable. If I want to select instances of other objects within it, how could I do so? e.g.

var element = $('header');
var list_element = element.('nav ul li:first') 

In this case I want to select the first list element of every ul of every nav within element.

Answer 1

您可以将变量用作选择器中的上下文，这将在内部调用 find() ：

var element = $('header');
var list_element = $('nav ul li:first', element) 

Answer 2

你应该使用find.

var list_element = element.find('nav ul li:first');

关于可读性的旁注。通常，当您将 jquery 对象存储在变量中时，它会以$. 如在

var $element = $('header');
var $list_element = $element.find('nav ul li:first');

Answer 3

var list_element = element.find('nav ul li:first') 

或者（根据您的评论）

$('header nav ul li:first')