Dependency Injection in AngularJS

• Dependency Injection is one of the best features of AngularJS.
• It is a software design pattern in which objects are passed as dependencies.
• It helps us to remove hard coded dependencies and makes dependencies configurable.
• Using Dependency Injection, we can make components maintainable, reusable and testable.

Dependency Injection is required for the following

• Separating the process of creation and consumption of dependencies.
• It allows us to create independent development of the dependencies.
• We can change the dependencies when required.
• It allows injecting mock objects as dependencies for testing.

AngularJS uses dependency with several types

• Value
• Factory
• Service
• Provider
• Constant