pure js has class code example

Example 1: javascript hasclass

if (document.body.classList.contains('thatClass')) {
    // do some stuff
}

Example 2: javascript hass class

if (myElement.classList.contains('someClassname')) {
    // do something
}

Example 3: query selector has clas

document.body.classList.add('thisClass');
// $('body').addClass('thisClass');

document.body.classList.remove('thatClass');
// $('body').removeClass('thatClass');

document.body.classList.toggle('anotherClass');
// $('body').toggleClass('anotherClass');