Get custom attribute value from select

February 25, 2022

I’m trying to clone a select options into another select. At the moment I’m able to do it but now the original option contains a custom attribute. So my question is how can I access to the custom attribute? This is what I have for now:

var options = $('#sel1 option');
var arrayOptions = [];
for (var i = 0; i < options.length; i++) {
    var id = parseInt($(options[i]).val(), 10);
    var text = $(options[i]).text() || '[select a type]';
            
    arrayOptions.push('<option value="' + id + ' data-custom="' + options[i]["data-custom"] + '">' + text + '</option>');
    
}
console.log(arrayOptions);

<select id="sel1">
    <option value="1" data-custom="abc1">Hello 1</option>
    <option value="2" data-custom="abc2">Hello 2</option>
    <option value="3" data-custom="abc3">Hello 3</option>
</select>

Right now options[i]["data-custom"] is setting undefined instead of abc1, abc2, etc.

Here is a fiddle.

>Solution :

You can use dataset.custom

var options = $('#sel1 option');
var arrayOptions = [];
for (var i = 0; i < options.length; i++) {
    var id = parseInt($(options[i]).val(), 10);
    var text = $(options[i]).text() || '[select a type]';
                
    arrayOptions.push('<option value="' + id + ' data-custom="' + options[i].dataset.custom + '">' + text + '</option>');
}
$('#result').text(arrayOptions.join("\n"));

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<select id="sel1">
<option value="1" data-custom="abc1">Hello 1</option>
<option value="2" data-custom="abc2">Hello 2</option>
<option value="3" data-custom="abc3">Hello 3</option>
</select>
<pre id="result"></pre>