Question

How jquery search a repeat text and get row id of other repeat row.

<tr id='1'>
   <td>AA</td>
</tr>
<tr id='2'>
   <td>BB</td>
</tr>
<tr id='3'>
   <td>AA</td>
</tr>
<tr id='4'>
   <td>AA</td>
</tr>
<tr id='5'>
   <td>BB</td>
</tr>
<tr id='6'>
   <td>CC</td>
</tr>
<tr id='7'>
   <td>BB</td>
</tr>

for example I want id 3,4(for AA) 5,7(for BB) and no id for CC because is no repeat.
thank you.

Answer 1

Something like this should work:

function repeats() {
    var seen = {};
    var ids = [];

    jQuery("tr").each(function() {
        var text = jQuery(this).find("td").text();

        if(!seen[text]) {
            seen[text] = 1;
        }

        else {
            seen[text]++;
        }

        if(seen[text] > 1) {
            ids.push(this.id);
        }
    });

    return ids;
}

Fiddle here