Multiple reducers are created to manage different areas of the state in a more organized way. It helps in maintaining code cleanliness and separation of concerns.
Multiple reducers can be combined using Redux’s
combineReducers
function. This function takes an object whose properties are different reducing functions, and merges them into a single reducing function.
State management as an immutable object is done by always returning a new state object instead of modifying the existing one. This is done to ensure predictability and simplicity of the state flow, and to facilitate debugging and testing.
Redux Docs: Using Combined Reducers
combineReducers
is a utility function to simplify the most common use case when writing ___ _____ .
combineReducers
is a utility function to simplify the most common use case when writing Redux reducers.
combineReducers
assembles the new state tree.
combineReducers
generates a function that calls every child reducer with the sliced state and combines their result into a single state object. The state produced from each reducer is stored by a key corresponding to the names of the reducers.
combineReducers
?
Initial state in an app using
combineReducers
is typically defined by providing default values in the individual reducers. The combined initial state would then be formed from the default states of each reducer.
Redux Docs: Combined Reducer Syntax
Splitting reducing functions as your app becomes more complex helps in maintaining the code’s manageability and clarity. It allows you to handle different parts of the state independently, and thus makes the code easier to understand and maintain.
The
combineReducers
helper function turns an object whose values are different reducing functions into a single reducing function you can pass tocreateStore
.
A popular convention when naming reducers is to use a noun describing the state slice they manage (like
todos
orusers
) as the key name in the combined reducer object. This allows for a clearer understanding of what state is being managed by each reducer.