Controller not a function, got undefined, while defining controllers globally

Question

I am writing a sample application using angularjs. i got an error mentioned below on chrome browser.

Error is

Error: [ng:areq] http://errors.

Answer 1

I had this error because I didn't understand the difference between angular.module('myApp', []) and angular.module('myApp').

This creates the module 'myApp' and overwrites any existing module named 'myApp':

angular.module('myApp', [])

This retrieves an existing module 'myApp':

angular.module('myApp')

I had been overwriting my module in another file, using the first call above which created another module instead of retrieving as I expected.

More detail here: https://docs.angularjs.org/guide/module