How to check whether particular html element is already present or not before inserting using Jquery

Question

I am new to Jquery, please help me. At present I am inserting asterisk class in the header , but I want to check one more condition, before inserting , Please help me how do I check that. At present its keep on inserting every Edit button click in the Grid. But I want to insert only once , If it is already present on the header then I should not insert again mycode, I am using Kendo Edit Grid-

edit: function (e) {
    var grid = this; e.container.find('td').each(function (_, x) 
       { 
         var cell = $(x);
         var input = cell.find('input[name]'); 
         if (input.attr('name')) { 
            var headerCell = grid.thead.find('th:eq(' + cell.index() + ')');
            headerCell.append($('')); 
         } 
      });
}

CSS class name -

.asterisk:after {
    content: " *";
    color: #b1001d;
}

Answer 1

I can give you the vanilla javascript code. because jquery isn't usefull anymore.

 if(typeof(element)!== 'undefined'){
//your code
//eg:
const newElement = '<h1>hello</h1>'
element.append(newElement)
}

Answer 2

我可以使用以下代码执行此操作：

 $('.asterisk').remove();