angular.js - What does a [] mean in angularjs?

Question

app.factory('Notes', ['$resource', function($resource) {
    return $resource('/notes/:id', null, {
        update: { method:'PUT' }
    }); 
}]);

It seems that the way of writing above is no different from the way of writing below. What's the difference? ?

app.factory('Notes', function($resource) {
    return $resource('/notes/:id', null, {
        update: { method:'PUT' }
    }); 
});

Answer 1

This is still available after it is called inline array annotation，目的是在代码被uglify.

You can try it. If you don’t pass [] processing and compress the code, it will definitely not run.

Please refer to Dependency Injection for details

Answer 2

There is no difference, but it is better to use the first way of writing. Because the second type is injected directly based on the formal parameters, if the code is compressed and $resource is compressed into something else, an error will be reported.