What happens if the component type changes? Will the same key help preserve the state?

When the component type in React changes (for example, from <Button> to <Input>), React perceives this as the removal of the old component and the creation of a new one. In this case, the state of the old component is not preserved, even if the key (key) remains the same. Keys help React identify components between renders, but they cannot preserve state when the component type changes.

In other words, the same key will not help preserve the state if the component type has changed — React will simply create a new instance of the component with a clean state.

Example:

// When changing the component type
{isInput ? <input key="unique" /> : <button key="unique">Click</button>}
// React will remove the input and create a button, and the input's state will not be preserved