javascript - How do I check if a checkbox is checked with JQuery?

Question

I am trying to allow a click function if the user has checked a checkbox on the page. Otherwise, I want to add a class to the #additional_foreign button.

I think I am close, but it doesn't seem to be working. Here is my code:

if($('#foreign_checkbox').attr('checked')) { 
    $('#additional_foreign').click(function() {
        alert('This click function works');
    });
} else {
    $('#additional_foreign').addClass('btn_disable');   
}

When I check the checkbox, it doesn't allow the click function and when I uncheck the checkbox, it also doesn't add the class as it should.

What am I doing wrong?

EDIT:Here is my HTML for clarification.

<input id="foreign_checkbox" type="checkbox" />
<span id="additional_foreign">Click Me</span>

Answer 1

try using $('#foreign_checkbox').is(":checked") - rest of the code looks fine

If this was my code I'd do something like this to make it work:

<input id="foreign_checkbox" type="checkbox" />
<span style='display:none' id="additional_foreign">Click Me</span>

<script type="text/javascript">
    $(document).ready(function() {

        $("#foreign_checkbox").click(function() {
            if($('#foreign_checkbox').is(':checked')) { 
                $('#additional_foreign').show();
            } else {
                $('#additional_foreign').hide();
            }
        });

        $('#additional_foreign').click(function() {
            alert('This click function works');
        });
    });
</script>