get inner elemt in jquery code example

Example 1: jquery get child div

$(this).children('div').show();

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