how to get id of div in jquery code example

Example 1: jquery get element id

$(this).attr('id')

Example 2: get id by this jquery

alert($(this).attr('id'))

Example 3: get id value jquery

$(document).ready(function(){
  $("button").click(function(){
  var myid = $( "#old" ).html()
    $("#some").html(myid);
  });
});