How to get the values from a table?

My question is pretty basic:

I have a table , I need to store in a variable all values of the line that was clicked, I'm trying this with this method below but the result is "undefined".

What could be wrong with the code? Or how could I do it?

 $(document).ready(function () {
    var table = $('#example2').DataTable();

    $('#example2 tbody').on('click', 'tr', function () {
        var data = table.row(this).data();
        alert(data[0]);
    });
});

  $(document).ready(function () {
    $('#example2').DataTable({
        "ajax": 'http://localhost:55959/Cliente/getBydesc?json=""',
        "columns": [
            { "data": "codigo" },
            { "data": "codinterno" },
            { "data": "razao" },
            { "data": "fantasia" },
            { "data": "cnpj" },
            { "data": "ie" },
            { "data": "cep" },
            { "data": "endereco" },
            { "data": "numero" },
            { "data": "complemente" },
            { "data": "bairro" },
            { "data": "cidade" },
            { "data": "uf" },
            { "data": "email" },
            { "data": "fone1" },
            { "data": "fone2" },
            { "data": "fone3" },
            { "data": "datacad" },
            { "data": "proprietario" }
        ],
        "columnDefs": [
             { "targets": [0, 2, 3, 18], "visible": true },
             { "targets": '_all', "visible": false },
             { "targets": [18], "width": "20%" },
             { "targets": [2, 3, 18], 'className': 'mdl-data-table__cell--non-numeric' },           
        ],
        "buttons": [
            'copy'
        ]
    });
});

html

 <table id="example2" class="display" cellspacing="0">
        <thead>
            <tr>
                <th>codigo</th>
                <th>codinterno</th>
                <th>razao</th>
                <th>fantasia</th>
                <th>cnpj</th>
                <th>ie</th>
                <th>cep</th>
                <th>endereco</th>
                <th>numero</th>
                <th>complemente</th>
                <th>bairro</th>
                <th>cidade</th>
                <th>uf</th>
                <th>email</th>
                <th>fone1</th>
                <th>fone2</th>
                <th>fone3</th>
                <th>datacad</th>
                <th>proprietario</th>
            </tr>
        </thead>          
    </table>