Additionally, you can enable complex data binding in sap-ui-core.js:
<script src="resources/sap-ui-core.js"
id="sap-ui-bootstrap"
data-sap-ui-libs="sap.ui.commons,sap.ui.table,sap.ui.ux3"
data-sap-ui-xx-bindingSyntax="complex"></script>
And then use both properties:
var oLabel = new sap.ui.commons.Label({
text : "{firstName} {lastName}"
});