Question

Let’s have a table like this:

<table>
 <tr>
  <td><input type="text" name="FirstName1" /></td>
  <td><input type="text" name="LastName1" /></td>
 </tr>
 <tr>
  <td><input type="text" name="FirstName2" /></td>
  <td><input type="text" name="LastName2" /></td>
 </tr>
</table>

I want to have a button that will add new row at the end of the table with incremented name attributes so it will look like this:

<table>
 <tr>
  <td><input type="text" name="FirstName1" /></td>
  <td><input type="text" name="LastName1" /></td>
 </tr>
 <tr>
  <td><input type="text" name="FirstName2" /></td>
  <td><input type="text" name="LastName2" /></td>
 </tr>
 <tr>
  <td><input type="text" name="FirstName3" /></td>
  <td><input type="text" name="LastName3" /></td>
 </tr>
</table>

And so on.

So far I have this but it does not increment name attributes:

$("#newRowButton").click(function(){
  $("table tr:last").clone().appendTo("table");
});

Answer 1

$("#newRowButton").click(function() {
  $("table tr:last")
      .clone()
      .appendTo("table")
      .find(':input')
      .attr('name', function(index, name) {
          return name.replace(/(\d+)$/, function(fullMatch, n) {
              return Number(n) + 1;
          });
      })
});

Live demo.