angularjs – Difference between scope declaration

Question:

Is there any difference in this scope declaration mentioned in the angular documentation:

myApp.controller('DoubleController', ['$scope', function($scope) {
  $scope.double = function(value) { return value * 2; };
}]);

for that scope?

myApp.controller('DoubleController', function($scope) {
  $scope.double = function(value) { return value * 2; };
});

apparently they both work equally the same

Answer:

Yes, there are differences.

The second uses the default service alias $scope , which is eponymous.

The first creates an injection of the $scope service, and uses the alias '$scope' to refer to this service.

This implementation allows for more flexibility – imagine a generic controller, which you can invoke by passing different services as a reference:

myApp.controller('DoubleController', ['servicoTipo1', function(servico) {
  servico.funcao();
}]);

myApp.controller('DoubleController', ['servicoTipo2', function(servico) {
  servico.funcao();
}]);

The controller implementation is the same, and the funcao() call is the same – but the services are different.

This template is often used when you want to implement reusable controllers :

myApp.controller('controleBase', function(servico) {
  servico.funcao();
});

myApp.controller(
    'controleDerivado1', [
        '$scope',
        '$controller',
        'servico1',
        function ($scope, $controller, servico) {

            $controller('controleBase', { $scope: $scope }); 
            //Invoca uma nova cópia de controleBase, 
            //utilizando servico como referencia de servico1; 
        }\);