能否在组件JS文件中直接连接Store？containers文件夹有何作用？

Absolutely! There’s no hard rule stopping you from using connect() (or modern React-Redux hooks like useSelector/useDispatch) directly in your component files. For smaller apps or straightforward components, this works perfectly fine—you’re not breaking any React/Redux best practices by doing so.

The containers folder (often paired with a separate components folder for "presentational" components) is a pattern focused on separation of concerns and keeping your codebase maintainable as it scales. Here’s why it’s valuable:

• Split presentation vs. logic: Components in the components folder stay as pure "UI-only" pieces—they only handle rendering based on props and trigger callbacks passed to them. Containers take care of all the Redux connection work: mapping state to props, dispatching actions, and handling data fetching or state updates. This makes your presentation components highly reusable (e.g., you could use the same RegistrationForm component with local state in one feature and connected to Redux in another).
• Easier testing: Presentational components are a breeze to test because they’re fully dependent on props—you don’t need to mock a Redux store to verify how they render or respond to user interactions. Containers can be tested separately to validate their Redux logic and data mapping.
• Cleaner code structure: As your app grows, having a dedicated space for store-connected components helps developers quickly locate where data flows are managed. It avoids cluttering UI-focused components with Redux-specific code that doesn’t relate to how things look.
• Centralized data transformation: Containers can act as a middle layer to prepare or transform data from the store before passing it to presentation components. For example, a RegistrationFormContainer might handle form validation, format input data, or wrap Redux dispatch actions into simpler callbacks that the form component can easily use.

内容的提问来源于stack exchange，提问作者Dennis Braun