useState
The useState composable creates a reactive and SSR-friendly shared state.
Usage
// Create a reactive state and set default valueconst count = useState('counter', () => Math.round(Math.random() * 100))
Because the data inside
useState
will be serialized to JSON, it is important that it does not contain anything that cannot be serialized, such as classes, functions or symbols.useState
is a reserved function name transformed by the compiler, so you should not name your own function useState
.Type
useState<T>(init?: () => T | Ref<T>): Ref<T>useState<T>(key: string, init?: () => T | Ref<T>): Ref<T>
key
: A unique key ensuring that data fetching is properly de-duplicated across requests. If you do not provide a key, then a key that is unique to the file and line number of the instance ofuseState
will be generated for you.init
: A function that provides initial value for the state when not initiated. This function can also return aRef
.T
: (typescript only) Specify the type of state