Need to understand Dependency Injection in Angular.js

Question

I am a newbie in Angular.js and came across a topic called \"Dependency Injection\". I am totally confused after reading the article.

As per the doc

Answer 1

I want to share of what I thought was a really great example of DI. I'm taking this example from the Angular.js documentation.

angular.module('xmpl.service', [])

  .value('greeter', {
    salutation: 'Hello',
    localize: function(localization) {
      this.salutation = localization.salutation;
    },
    greet: function(name) {
      return this.salutation + ' ' + name + '!';
    }
  })

  .value('user', {
    load: function(name) {
      this.name = name;
    }
  });

angular.module('xmpl.directive', []);

angular.module('xmpl.filter', []);

angular.module('xmpl', ['xmpl.service', 'xmpl.directive', 'xmpl.filter'])

  .run(function(greeter, user) {
    // This is effectively part of the main method initialization code
    greeter.localize({
      salutation: 'Bonjour'
    });
    user.load('World');
  })

  .controller('XmplController', function($scope, greeter, user){
    $scope.greeting = greeter.greet(user.name);
  });

This code defines a separate module for directive, filter and service. As written in the documentation:

Run blocks are the closest thing in Angular to the main method.

So, the xmpl module has 3 dependencies which are injected using DI.