Dynamically create DOM object and give class

Question

I'm dynamically creating option elements for a drop down menu using Javascript and would like to know how to add a class to them so that I can style them with CSS.

I have the following code:

for (var i=0;i<portfolio.length-1;i++) {
    portfolioSelect.options[portfolioSelect.options.length] =
        new Option(portfolio[i]);
}

where portfolio is an array populated by an outside source.

HTML where options inserted:

<select id="portfolio" name="portfolio">
    <option selected="selected" value="Select One">Select One</option>
</select>

Answer 1

for (i=0;i<portfolio.length-1;i++) {
    var option = new Option(portfolio[i]);
    option.setAttribute('class', 'your-class-name');
    portfolioSelect.options[portfolioSelect.options.length] = option;
}

Answer 2

You can assign class name(s) to the className property, e.g.:

var opt;
for (var i=0;i<portfolio.length-1;i++) {
    opt = new Option(portfolio[i]);
    opt.className = "your_class_name_here";
    portfolioSelect.options[portfolioSelect.options.length] = opt;
}

This is true of any DOM element. className reflects the class attribute on the element (it's named that way because class is a reserved word in Javascript). The value is exactly like the attribute, which means it can multiple classes separated by spaces.