Sencha/ExtJs: How I find the version used in an application?

One time or another, everyone will need to ask this question: How I find the ExtJs/Sencha version used in an application?

In ExtJS, Ext.version defines the version used, however, in ExtJS 4.x, Ext.version has been replaced by Ext.getVersion(). But we don’t assume that Ext.version=3.x and Ext.getVersion()=4.x, so the below code detects the version of Sencha used:

if (Ext.version != undefined) {
    alert(Ext.version);
} else {
    alert(Ext.getVersion());
}

For example:

Best regards,