How to jQuery clone() and change id?

$('#cloneDiv').click(function(){


  // get the last DIV which ID starts with ^= "klon"
  var $div = $('div[id^="klon"]:last');

  // Read the Number from that DIV's ID (i.e: 3 from "klon3")
  // And increment that number by 1
  var num = parseInt( $div.prop("id").match(/\d+/g), 10 ) +1;

  // Clone it and assign the new ID (i.e: from num 4 to ID "klon4")
  var $klon = $div.clone().prop('id', 'klon'+num );

  // Finally insert $klon wherever you want
  $div.after( $klon.text('klon'+num) );

});

<script src="https://code.jquery.com/jquery-3.1.0.js"></script>

<button id="cloneDiv">CLICK TO CLONE</button> 

<div id="klon1">klon1</div>
<div id="klon2">klon2</div>

Scrambled elements, retrieve highest ID

Say you have many elements with IDs like klon--5 but scrambled (not in order). Here we cannot go for :last or :first, therefore we need a mechanism to retrieve the highest ID:

const $all = $('[id^="klon--"]');
const maxID = Math.max.apply(Math, $all.map((i, el) => +el.id.match(/\d+$/g)[0]).get());
const nextId = maxID + 1;

console.log(`New ID is: ${nextId}`);

<div id="klon--12">12</div>
<div id="klon--34">34</div>
<div id="klon--8">8</div>

<script src="https://code.jquery.com/jquery-3.1.0.js"></script>

Update: As Roko C.Bulijan pointed out.. you need to use .insertAfter to insert it after the selected div. Also see updated code if you want it appended to the end instead of beginning when cloned multiple times. DEMO

Code:

   var cloneCount = 1;;
   $("button").click(function(){
      $('#id')
          .clone()
          .attr('id', 'id'+ cloneCount++)
          .insertAfter('[id^=id]:last') 
           //            ^-- Use '#id' if you want to insert the cloned 
           //                element in the beginning
          .text('Cloned ' + (cloneCount-1)); //<--For DEMO
   }); 

Try,

$("#id").clone().attr('id', 'id1').after("#id");

If you want a automatic counter, then see below,

   var cloneCount = 1;
   $("button").click(function(){
      $("#id").clone().attr('id', 'id'+ cloneCount++).insertAfter("#id");
   }); 

This is the simplest solution working for me.

$('#your_modal_id').clone().prop("id", "new_modal_id").appendTo("target_container");