Скачать или смотреть Get State from the Redux Store

The getState() method in Redux is a core function provided by the Redux store object. Its purpose is to return the current state tree of the application. This state tree represents the entire data managed by your Redux store at a given moment.
Key characteristics of getState():
Synchronous:
getState() is a synchronous function, meaning it returns the state immediately when called.
Returns the entire state:
It provides access to the complete state object, including all the slices of state managed by your different reducers.
Non-reactive:
Calling getState() directly does not automatically re-render components or trigger updates when the state changes. For reactive updates in React components, useSelector (from React Redux) is the preferred method as it subscribes to state changes and re-renders the component when relevant parts of the state change.
Direct state reference:
getState() returns a direct reference to the current state object. This means it is crucial to avoid direct mutations of the returned state object, as this can lead to unpredictable behavior and violate Redux's immutability principles. All state updates should be performed by dispatching actions that are handled by pure reducer functions, which return new state objects.

When to use getState():
While useSelector is generally preferred for accessing state in React components, getState() can be useful in specific scenarios, such as:
Inside Redux Thunks:
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Thunks are action creators that can contain asynchronous logic and have access to dispatch and getState. This allows you to perform conditional logic or fetch additional data based on the current state before dispatching further actions.
For debugging or logging:
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You can use getState() to inspect the current state of your application for debugging purposes.
In non-component logic:
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When you need to access the state outside of a React component, such as in utility functions or middleware.