Question

I’m trying to perform a simple replace(); method in JavaScript where I’d like to remove every class from an HTML element except a specific one, how can I do it?

I tried this without success:

<div id="my_div" class="hello letsgo baby is_checked cool">Gordon Freeman</div>

<script>
$(document).ready(function () {
    alert ($(#my_div).attr("class").replace (/^(is_checked)$/, ""));
    // id'like it returns "is_checked" or "" to work like a boolean;
});
</script>

Answer 1

You’re trying to alert is_checked when it’s there, right? Try using .hasClass:

$(document).ready(function () {
    if($("#my_div").hasClass("is_checked")) {
        alert("is_checked");
    }
    else {
        alert("");
    }
});

If you just want to know whether an element has a certain class on it, this returns true or false telling you exactly that:

$("#my_div").hasClass("is_checked")