jQuery addClass example

Change class name on click in jQuery

HTML

<head> <script type="text/javascript" defer charset="utf8" src="https://cdn.datatables.net/1.10.20/js/jquery.dataTables.min.js"></script>
    <script src="js/script.js" defer></script>
    <link rel="stylesheet" type="text/css" href="https://cdn.datatables.net/1.10.20/css/jquery.dataTables.css">
</head>


<table id="example" class="stripe">
    <select name="query-select" size="1">
        <option value="year">year</option>
        <option value="months">months</option>
    </select>
    <tbody>
    </tbody>
</table>

JavaScript

const dataArr = [
    {
        "firstname":"Виктор",
        "lastname":"Петров",
        "email":"[email protected]",
        "phonenumber":"77777777777",
        "birthday_contact":"1981-03-03",
        "company":"Company 1"
    },
    {
        "firstname":"Вася",
        "lastname":"Пупкин",
        "email":"[email protected]",
        "phonenumber":"333333333333",
        "birthday_contact":"2004-10-20",
        "company":"Company 2"
    },
    {
        "firstname":"Дима",
        "lastname":"Коршунов",
        "email":"[email protected]",
        "phonenumber":"22222222222",
        "birthday_contact":"1991-07-16",
        "company":"Company 3"
    },
    {
        "firstname":"Сан",
        "lastname":"Саныч",
        "email":"[email protected]",
        "phonenumber":"33333333333",
        "birthday_contact":"1998-07-03",
        "company":"Company 4"
    },

    {
        "firstname":"Змей",
        "lastname":"Горыныч",
        "email":"[email protected]",
        "phonenumber":"33333333333",
        "birthday_contact":"1998-11-03",
        "company":"Company 4"
    }
];

function addEvent () {
    const select = $('select[name="query-select"]');

    select.change(function (e) {

        if(e.target.value === 'months'){
               $('#example').dataTable({
                    columnDefs: [{
                        dorderData: [7],
                        targets: [4],
                        aDataSort: [7]
                    }]
                })
        }
        if(e.target.value === 'year'){
            table.destroy();
            trigger = 'year';
            table = $('#example').DataTable(setDataToTable(dataArr));
        }
    });
}
addEvent();

function getYear(obj) {
    const index = obj.birthday_contact.indexOf('-');
    const year = obj.birthday_contact.slice(0, index);
    return year;
}

function getMonths(a) {
    const index = a.birthday_contact.indexOf('-');
    const secondIndex = a.birthday_contact.slice(index+1,...