prevent users to check max 3/x items from a checkbox group - Fluent Forms

fluentform-checkbox-max-restriction.js

/**
 * Function to prevent users mark more than expected items.
 * This code must need to be placed in custom JS of your form 
 * @param: containerClass String - The contaner class of the target checkbox block. 
 *           You can add a custom container class in the form settings
 *
 * @param: maxChecked Integer - Max Number of items user can mark
 * @return: void
 *
 */

function maxItemsCheck(containerClass, maxChecked) {
    var checkboxes = $form.find('.'+containerClass+' input');
    checkboxes.on('change', function() {
        var count = $form.find('.'+containerClass+' input:checked').length;
        if(count > maxChecked) {
            alert('You can not check more than '+maxChecked+' items');
            $(this).prop('checked', false);
        }
    });
}

// Example Use case
maxItemsCheck('max_3_items', 3);