function hasClass(el, className) {
    if (el.classList)
        return el.classList.contains(className);
    return !!el.className.match(new RegExp('(\\s|^)' + className + '(\\s|$)'));
}


function addClass(el, className) {
    if (el.classList)
        el.classList.add(className)
    else if (!hasClass(el, className))
        el.className += " " + className;
}

function removeClass(el, className) {
    if (el.classList)
        el.classList.remove(className)
    else if (hasClass(el, className)) {
        let reg = new RegExp('(\\s|^)' + className + '(\\s|$)');
        el.className = el.className.replace(reg, ' ');
    }
}

export {addClass, removeClass}