How does AngularJS recognize a function as controller directive -

How does AngularJS recognize a function as controller directive -

i looking @ angular api reference. says ngcontroller directive, , give next example:

function settingscontroller($scope) { $scope.name = "john smith"; }

this looks plain javascript function, argument $scope passed in. thought define directives, need call:

app.directive("name", func())

does angular treats function $scope argument controller directive? or if modify dom element include ng-controller = "settingscontroller" settingscontroller interpreted such?

ngcontroller directive (directives referred in dom--angular allows specify directives via tag names, attributes, class names , comments). ngcontroller directive written create controller instance based on name passed in directive (in case string "settingscontroller". function not directive.

angularjs angularjs-directive