Check if a class is affecting the style of an element.

check-class.js

(function() {
    var affected = [], unaffected = [],
        className;

    className = prompt('Class to check:');
    if (!className) return;

    $('.' + className).each(function() {
        var element = this,
            $element = $(this),
            before = [], after = [];

        var styleProps = Object.keys(JSON.parse(JSON.stringify(element.style)));

        var before = [], after = [];

        styleProps.forEach(function(style) {
            before.push($element.css(style));
        });

        $element.removeClass(className);

        styleProps.forEach(function(style) {
           after.push($element.css(style));
        });

        $element.addClass(className);

        if (before.join('') === after.join('')) {
            unaffected.push(element);
        }
        else {
            affected.push(element);
        }
    });

    console.log(affected.length + ' element(s) DO have styles applied from the ' + className + ' class.');
    affected.forEach(function(el) { console.log(el); });

    console.log(unaffected.length + ' element(s) do NOT have styles applied from the ' + className + ' class.');
    unaffected.forEach(function(el) { console.log(el); });
})();