The Difference Between a Service, Factory, and Provider in AngularJS

When it comes to AngularJS, understanding the differences between a service, factory, and provider is crucial for developing efficient and maintainable code.

Service

A service in AngularJS is a constructor function that is instantiated with the "new" keyword. Services are singletons, meaning they are instantiated only once per application and can be accessed throughout the application. They are ideal for sharing data and functionality across different parts of the application.

Factory

A factory in AngularJS is a function that returns an object. Factories are used to create objects, which can be of any type, and are helpful in creating instances of objects that can be reused throughout the application. Factories are also singletons and are instantiated only once per application.

Provider

A provider in AngularJS is the most configurable and flexible of the three. Providers are used to create services that can be configured before the application starts. Providers can be injected with a configuration function that allows them to be customized based on the application's needs.

In summary, the key difference between a service, factory, and provider in AngularJS is in how they are instantiated and their level of configurability. Services and factories are both singletons, while providers offer more flexibility for customization.

For more information on services, factories, and providers in AngularJS, consult the official AngularJS documentation.