Why to use 'defaultProvider' for useContext?-CodePudding

I am watching his video about useContext but he is not using defaultProvider, but the template we purchased use it, why? What advantage it has?

https://www.youtube.com/watch?v=5LrDIWkK_Bc

const defaultProvider: AuthValuesType = {
    userDTO: null,
    handleAuth: () => Promise.resolve(),
    logout: () => Promise.resolve(),
    updateUserDTO: () => Promise.resolve(),
}

const AuthContext = createContext(defaultProvider)

In the same file an AuthProvider is set up, and 'real' states get assigned. Then why to use the default?

CodePudding user response：

The defaultProvider value is passed to the createContext method as the default value for the context. This default value is used when a component uses the useContext hook and does not have a matching provider above it in the component tree. In other words, the defaultProvider is a fallback value that is used when the context value is not provided by a provider.

The purpose of using a default value is to avoid having to check whether the context value is null or undefined every time you use it in a component. With the default value in place, you can use the context value directly in your components without having to worry about checking for its existence.

In the case of the AuthContext, the default provider likely contains some default values for the context properties, such as null for the userDTO property and some empty functions for the other properties. This allows the components that use the AuthContext to assume that these properties are always defined and avoid having to check for their existence.

Overall, using a default value for the context can make your code simpler and more straightforward, especially if the context is used in many different components in your application.