Parent and child selection, can't access first parent (jquery)

Question

I have a problem with a parent/child selection with jquery.

I have a HTML page who looks like this:

<tr> 
   <input type='checkbox' /> //1st checkbox
   <.. some stuff ../>
</tr>
<tr>
   <td><input type='checkbox' /></td> //2nd checkbox
   <td>
     <select id='stateChanger' onchange='stateChanger();'/>
       <option> ...</option>
       ...
   </td> 
</tr>

I want to check the checkbox of the line I changed with my select at the moment I changed it. But with the code hereinbelow I only check the first checkbox.

function stateChanger(){

        $('#stateChanger').parent().parent().children('td').children("input[type='checkbox']").attr("checked","true");
}

If anyone has idea to help me, I can post the full code. Thanks. Victor

Answer 1

You can use:

function stateChanger(obj) {
  $(obj).closest("tr").find("td:first input[type='checkbox']").attr("checked", "true")
}

and add this to onchange='stateChanger();' so it will be onchange='stateChanger(this);'

This will check the second <input type='checkbox' />

demo

function stateChanger(obj) {
  $(obj).closest("tr").find("td:first input[type='checkbox']").attr("checked", "true")
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<table>
  <tr>
    <input type='checkbox' />
  </tr>
  <tr>
    <td><input type='checkbox' /></td>
    <td>
      <select id='stateChanger' onchange='stateChanger(this);' />
      <option> ...</option>
      <option>texst</option>
    </td>
  </tr>
</table>