Toggle input disabled attribute using jQuery

$('#el').prop('disabled', (i, v) => !v);

The .prop() method accepts two arguments:

• Property name (disabled, checked, selected) anything that is either true or false
• Property value, can be:
• (empty) - returns the current value.
• boolean (true/false) - sets the property value.
• function - Is executed for each found element, the returned value is used to set the property. There are two arguments passed; the first argument is the index (0, 1, 2, increases for each found element). The second argument is the current value of the element (true/false).

So in this case, I used a function that supplied me the index (i) and the current value (v), then I returned the opposite of the current value, so the property state is reversed.

Another simple option that updates on a click of the checkbox.

HTML:

<input type="checkbox" id="checkbox/>
<input disabled type="submit" id="item"/>

jQuery:

$('#checkbox').click(function() {
    if (this.checked) {
        $('#item').prop('disabled', false); // If checked enable item       
    } else {
        $('#item').prop('disabled', true); // If checked disable item                   
    }
});

In action: link

I guess to get full browser comparability disabled should set by the value disabled or get removed!
Here is a small plugin that I've just made:

(function($) {
    $.fn.toggleDisabled = function() {
        return this.each(function() {
            var $this = $(this);
            if ($this.attr('disabled')) $this.removeAttr('disabled');
            else $this.attr('disabled', 'disabled');
        });
    };
})(jQuery);

Example link.

EDIT: updated the example link/code to maintaining chainability!
EDIT 2:
Based on @lonesomeday comment, here's an enhanced version:

(function($) {
    $.fn.toggleDisabled = function(){
        return this.each(function(){
            this.disabled = !this.disabled;
        });
    };
})(jQuery);

    $('#checkbox').click(function(){
        $('#submit').attr('disabled', !$(this).attr('checked'));
    });