What is dependency injection in Web API?

Updated Apr 28, 2026

Short answer

DI provides dependencies to classes instead of creating them.

Deep explanation

Dependency Injection improves testability and decoupling by injecting services via constructor.

Real-world example

Injecting database services.

Common mistakes

  • Manual instantiation instead of DI.

Follow-up questions

  • What is IoC?
  • Why DI?

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