how to find element by class name in jquery code example

Example 1: jquery: get class list using element id

$('#elementID').prop('classList').add('yourClassName')
$('#elementID').prop('classList').remove('yourClassName')

Example 2: jquery find tag and class

$(".txtClass")                  =>  getElementsByClassName()

$("#childDiv2 .txtClass")       =>  getElementById(),
                                    then getElementsByClassName()

$("#childDiv2 > .txtClass")     =>  getElementById(),
                                    then iterate over children and check class

$("input.txtClass")             =>  getElementsByTagName(),
                                    then iterate over results and check class

$("#childDiv2 input.txtClass")  =>  getElementById(),
                                    then getElementsByTagName(),
                                    then iterate over results and check class