Confused about Service vs Factory

Question

As I understand it, when inside a factory I return an object that gets injected into a controller. When inside a service I am dealing with the object using this

Answer 1

I had this confusion for a while and I'm trying my best to provide a simple explanation here. Hope this will help!

angular .factory and angular .service both are used to initialize a service and work in the same way.

The only difference is, how you want to initialize your service.

Both are Singletons

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var app = angular.module('app', []);

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Factory

app.factory(, )

If you would like to initialize your service from a function that you have with a return value, you have to use this factory method.

e.g.

function myService() {
  //return what you want
  var service = {
    myfunc: function (param) { /* do stuff */ }
  }
  return service;
}

app.factory('myService', myService);

When injecting this service (e.g. to your controller):

• Angular will call your given function (as myService()) to return the object
• Singleton - called only once, stored, and pass the same object.

---

Service

app.service(, )

If you would like to initialize your service from a constructor function (using this keyword), you have to use this service method.

e.g.

function myService() {
  this.myfunc: function (param) { /* do stuff */ }
}

app.service('myService', myService);

When injecting this service (e.g. to your controller):

• Angular will newing your given function (as new myService()) to return the object
• Singleton - called only once, stored, and pass the same object.

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NOTE: If you use factory with or service with , it will not work.

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Examples - DEMOs

• Angular Service vs Factory
• Angular Service vs Factory (with route)