Chapter 5. Scope: a fresh breath of state

"Still this planet's soil for noble deeds grants scope abounding."

—Johann Goethe

In one sentence, scope is a fixed duration of time or method calls in which an object exists. In other words, a scope is a context under which a given key refers to the same instance. Another way to look at this is to think of scope as the amount of time an object's state persists. When the scope context ends, any objects bound under that scope are said to be out of scope and cannot be injected again in other instances.

State is important in any application. It is used to incrementally build up data or responsibility. State is also often used to track the context of certain processes, for instance, to track objects in the same ...

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