Require in javascript

Question

What does this mean in javascript? I have just started using ext-js. And the first line in sample header file is

Ext.require('Ext.tab.*');

What does this mean ?

Answer 1

That call is used for dynamic loading of classes/scripts:

Ext - Sencha Docs - Ext JS 4.0

So your call is dynamically loading all of the classes in the Ext.tab namespace (since you're using a wildcard expression).