Use this directive to auto-bootstrap an AngularJS application. The ngApp directive designates the root element of the application and is typically placed near the root element of the page - e.g. on the
or tags.Use this directive to auto-bootstrap an AngularJS application. The ngApp directive designates the root element of the application and is typically placed near the root element of the page - e.g. on the or tags.
Only one AngularJS application can be auto-bootstrapped per HTML document. The first ngApp found in the document will be used to define the root element to auto-bootstrap as an application. To run multiple applications in an HTML document you must manually bootstrap them using angular.bootstrap instead. AngularJS applications cannot be nested within each other.
You can specify an AngularJS module to be used as the root module for the application. This module will be loaded into the $injector when the application is bootstrapped. It should contain the application code needed or have dependencies on other modules that will contain the code. See angular.module for more information.
In the example below if the ngApp directive were not placed on the html element then the document would not be compiled, the AppController would not be instantiated and the {{ a+b }} would not be resolved to 3.
ngApp is the easiest, and most common way to bootstrap an application.