How JQ gets the ID name of an element

html:

<div class="box" id="mybox"></div>

To get the id value , Can pass jquery Of attr() Method .

Examples are as follows ：

var idName = $('.box').attr('id')
alert(idName)

Pop up results ：

expand ：

attr() Method ： Used to set or return the attributes and values of the selected element .
alert() Method ： Used to display with a specified message and a OK Button warning box .