What is he doing! Array <string> = mean in angular?

Question

I read the AngularJS documentation and found some type of parameter

!Array.<string>=

What does it mean? any answer will clarify the situation.

Answer 1

Operators from Google Closure Type of expression .

• ! identifies the type as "Non-nullable".
• <...> identifies the content type of an object / collection.
• = identifies the parameter as "Optional."

So, in the case of angular.module():

• There are no arguments for requires.
• When given, it cannot nulland must be Arraycontaining only string values.

angular.module('Foo');               // valid arguments
angular.module('Foo', null);         // not valid
angular.module('Foo', ['Bar']);      // valid
angular.module('Foo', [false]);      // not valid
angular.module('Foo', function(){}); // valid