Using global states
In this section, we will learn what a global state is again and when we should use it.
What is a global state?
In this book, a global state simply means that it's not a local state. If a state conceptually belongs to a single component and is encapsulated by the component, it is a local state. Hence, if a state doesn't belong to a single component and can be used by multiple components, it is a global state.
There could be an application-wide local state that all components depend on. In this case, the application-wide local state can be seen as a global state. In this sense, we can't clearly divide local states and global states. In most cases, if you consider where a state conceptually belongs, you can work out whether it's local or global.
There are two aspects when people talk about a global state, as outlined here:
- One is a singleton, meaning that in some contexts, the state has one value.
- The other is a shared state...