Ajouter supprimer une tr dans une table avec l'insertion des options sur une balise select

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<html>
<head>
<title>AJOUTER SUPPRIMER UNE TR DANS UNE TABLE | par NGLESSON </title>
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<meta name="keyword" content="AJOUTER SUPPRIMER UNE TR DANS UNE TABLE">
<meta name="author" content="Mezgani said">
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</head>
<body>

  <div class="container"> 
    <div class="row mt-5"> 
      <div class="table-responsive mt-2"> 
        <button class="btn btn-md btn-info mb-2 mb-2" id="addrow" type="button"> <i class="fa fa-plus"></i> Ajouter un nouveau </button> 
        <table class="table table-bordered table-hover table-count"> 
          <thead> 
            <tr> 
              <th class="text-center">N° Colone</th> 
              <th class="text-center">Quantité</th> 
              <th class="text-center">Action</th> 
            </tr> 
          </thead> 
          <tbody id="tbody"> 
           <tr id="R1">
              <td class="row-index text-center">1</td>
              <td class="text-center"><select id="inputcountry" name="inputcountry" class="form-control 1_inputcountry"></select></td>
              <td class="text-center"><button class="btn btn-danger btn-sm btn-remove" type="button"><i class="fa fa-trash"></i></button></td>
           </tr>      
           </tbody> 
        </table> 
      </div> 
    </div> 
    </div> 
    
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</body>
</html>

$(document).ready(function () { 
  var rowIdx = 1; 
  var uniq = rowIdx;
  optionList(uniq);
      $('#addrow').on('click', function () {  
        uniq = new Date().getUTCMilliseconds()+''+Math.floor(Math.random() * 100);
        $('#tbody').append('<tr id="R'+ ++rowIdx +'">' 
          +'<td class="row-index text-center"><p>'+rowIdx+'</p></td>' 
          +'<td class="text-center"><select id="inputcountry" name="inputcountry" class="form-control '+uniq+'_inputcountry"></select></td>'
          +'<td class="text-center"><button class="btn btn-danger btn-sm btn-remove" type="button"><i class="fa fa-trash"></i></button></td>'
          +'</tr>'); 
          optionList(uniq);
      }); 
      // jQuery button click event to remove a row. 
      $('#tbody').on('click', '.btn-remove', function () { 
        if($(".table-count #tbody tr").length > 1){
          // Getting all the rows next to the row 
          // containing the clicked button 
          var child = $(this).closest('tr').nextAll(); 
          // Iterating across all the rows  
          // obtained to change the index 
          child.each(function () { 
            // Getting <tr> id. 
            var id = $(this).attr('id'); 
            // Getting the <p> inside the .row-index class. 
            var idx = $(this).children('.row-index').children('p'); 
            // Gets the row number from <tr> id. 
            var dig = parseInt(id.substring(1)); 
            // Modifying row index. 
            idx.html(dig - 1); 
            // Modifying row id. 
            $(this).attr('id', 'R'+dig - 1); 
          }); 
          // Removing the current row. 
          $(this).closest('tr').remove(); 
          // Decreasing total number of rows by 1. 
          rowIdx--; 
        }else{
          alert("You cannot delete first tr");
        }
      }); 
}); 
function optionList(nbr){
  var min = 0,max = 100;
  var elm;
  elm = ""+nbr+"_inputcountry";
  for (var i = min; i<=max; i++){
    var opt = document.createElement('option');
    opt.value = i;
    opt.innerHTML = i;
    opt.title = i;
    document.getElementsByClassName(elm)[0].appendChild(opt);
  }
}