In angular 1, if you had a function on the form
myApp.controller('MyCtrl', function($myCoolService) {
//...
});
Angular would see that you are looking for a parameter named myCoolService, see if it already has it, and then inject it when calling your controller.
This of course broke in various ways with minification when the parameter names were mangled. So one had the opportunity to use "array syntax", requesting a dependency by a string. Or use a preprocessor in the build script adding the array syntax before minifying.
