Providers in Angular

What is the provider?

So, we’ve had a look at what Injectors are and the various levels of Injectors in Angular, but now we are going to have a look at providers. We have seen them briefly already, but it’s worth having a more in-depth look at them and the role they fulfill in Angular.

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The Injector needs a provider to create the instances (versions) of the classes being injected into all the components, services, and directives.

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The way this relationship between injector and provider is set up is through a token that the injector uses at runtime to create the required class that the provider needs. So, when our application is running and a class is needed via Dependency Injection, the token that the provider gives makes sure that the class being used is the one with the correct token.