jsLint error "Cannot set property 'first' of undefined"

Question

Run jsLint on this fiddle. The script runs, but what is jsLint telling me when it says "Problem at line 7 character 18: Cannot set property 'first' of undefined"?

Update with sample code fiddle:

(function($) {
    $.fn.selectBox = function(data) {
        for (var x = 0; x < data.length; x++) {
        }

        return this;
    };
})(jQuery);

Answer 1

It's because you're defining the variable for the for statement inside of it. Declare it outside and solved!. I fixed a few other warnings. http://jsfiddle.net/SXajC/87/