React-Redux API documentation symbols

Question

I'm reading the react-redux documentation and I found this:

[mapStateToProps(state, [ownProps]): stateProps] (Function)

I don't understand exactly what " [ ] " means, or what is the " : " symbol used for in this context. I remember that jQuery also uses this for it's API documentation. Example:

.slideToggle([duration][,complete])

Is there any convention for writing/reading these?

Answer 1

“ []”表示不是必需的，但可以使用。

Answer 2

Brackets indicate that a parameter is optional, colons indicate some kind of type declaration.

So, for mapStateToProps : it is an optional argument to connect . It should always be declared with a first parameter which will be the Redux state tree, and may be declared to take a second parameter which will be the props given to the wrapper component.