drakvuf

//jQuery
var el = $('.example');
el.addClass('className');

//native Js
var el = document.querySelector('.example');
el.classList.add('className');

drakvuf

//jQuery
var el = $('.example');
el.removeClass('className');

//native Js
var el = document.querySelector('.example');
el.classList.remove('className');

drakvuf

//jQuery
var el = $('.example');
el.toggleClass('className');

//native Js
var el = document.querySelector('.example');
el.classList.toggle('className');

drakvuf

//jQuery
var el = $('.example');
el.hasClass('className');

//native Js
var el = document.querySelector('.example');
el.classList.contains('className');

drakvuf

valami: {
  if (countrySelect.val() != '' && addressInput.val() != '') {
    if (Number(addressInput.val()) && countrySelect.val() == 'Deutschland') {
      for (var i = 0; i < merchants.length; i++) {
        var merchant = merchants[i];
        var mz = merchant.zip_code.toString();
        var aiv = addressInput.val().toString();
        if (mz.indexOf(aiv) == 0 && merchant.fullCountryName == 'Deutschland') {
          address_string = merchant.zip_code + ' ' + merchant.city;
          console.log(merchant.zip_code + ' ' + merchant.city);

drakvuf

var add = function(x) {
  return function(y) {
    return x + y;
  };
};

var increment = add(1);
var addTen = add(10);

increment(2);

drakvuf

//jQuery
$('.class-name');

//Javascript
document.querySelectorAll('.class-name');

drakvuf

//jQuery
$('.class-name-one', '.class-name-two');

//Javascript
document.querySelectorAll('.class-name-1, .class-name-2');

drakvuf

var el = document.querySelector('.element');
//előző elem -> textnode-al térhet vissza!
var prevEl = el.previousSibling;
//előző elem meglepetések nélkül
var prevEl = el.previousElementSibling;
//előző elem -> textnode-al térhet vissza!
var nextEl = el.nextSibling;
//következő elem meglepetések nélkül
var nextEl = el.nextElementSibling;

drakvuf

//elemek kiválasztása
var el = querySelectorAll('.elements');
//első elem
var firstEl = el[0];
//utolsó elem
var lastEl = el[el.length - 1]