Get ID value of a dojo combobox selected item - dojo

Question

var xhrArgs = {
url: "../Person/GetAll",
handleAs: "json",
preventCache: true,
load: function (data, ioargs) {
var jsonString = dojo.toJson(data)
var dataStore = new dojo.store.Memory({ data:
dojo.fromJson(jsonString) });
var personCmb = dijit.byId('cmbSingers');
if (personCmb == null)
{
var cobox = new dijit.form.ComboBox({ id: "cmbSingers", name: "Name", store: dataStore, searchAttr: "Name" }, "cmbSingers");
cobox.startup();
}
function cmbSingers_OnSelected() {
alert(dijit.byId('cmbSingers').get('value')); **this return the Text, But I want to get Id of Select value**
}

Answer 1

For anyone looking for a solution to this in 2016+...
I ran into the same situation and found a way to get the value of selected options from Dojo ComboBox. Instead of just using .value or .get('value'), use .item.value:
dijit.byId('someComboBox').item.value
.item will return an Object like this for you to use:
Object {id: "1", value: "1", name: "One"}
To elaborate... say you define the options for your ComboBox by using a select like so:
<select dojoType="dijit.form.ComboBox" id="someComboBox" maxlength="30">
<option value=""></option>
<option value="1">One</option>
<option value="2">Two</option>
<option value="3">Three</option>
</select>
Say you select the "One" option.
Calling dijit.byId('someComboBox').value will return "One",
but calling dijit.byId('someComboBox').item.value will return "1"

Answer 2

Mkay, json is like so?
{ identifier: 'Id', items: [ { Id: '1', name:'foo', age: 12 }, { Id: '2', name:'bar', age: 30 } ] }
And you have dijit.form.ComboBox in variable cobox, your dojo.data.ItemFileReadStore in variable store.
dojo.connect(cobox, "onChange", function() {
var val = this.get("value"),
id = "",
matcher = new RegExp("^" + val + "$");
dojo.some(store._arrayOfAllItems, function(item, idx) {
if(matcher.test(store.getValue(item, "name")) {
id = store.getValue(item, "Id");
return true; // breaks .some loop
}
});
});