The value() method, called without any parameters, will return the selected items’s value of the ComboBox widget.
The value(valueToSelect) method is used to select item by its value.

<input id="combo" />

<script type="text/javascript">
    $(function () {
            dataSource: {
                data: countries
            textTemplate: "{name}",
            valueTemplate: "{code}",
            inputTemplate: "{name}"

        $("#combo").swidget().value(); // returns an empty array
        $("#combo").swidget().value(1); // selects the item with value (in this case {code}) equals to 1
        $("#combo").swidget().value(); // returns an array with one element - the selected item's value - 1