What is the difference between the parameters of the ts function (callback?: () = > void) and (callback?:void)?

function render (callback?: () = > void): string
the parameter of the ts function means that the return value of callback is the return value of the function. The return value of the function is void

The argument to the ts function

function render (callback?:void): string
means that the return value of callback is void

am I right to understand this?

Typescript javascript
Mar.22,2021

callback?: () = > void, indicates that callback is a function type and does not return a value. It does not mean that the return value is a function. It is written here by ts itself, which not only means the arrow function, but also specifies the parameter type and return value of the function.

callback?:void cannot prove that callback is a function. Ts will think that callback is of type void. You must have reported an error in passing the function.

there's nothing wrong with your understanding. You can actually get a type alias

. 
type Callback = () => void;
function render(callback: Callback):string{}

Previous: What files should vue-cli assets and static put respectively?

Next: Under what circumstances will the server return 100? What is the application scenario?

css mysql arrays josn react html typescript webpack npm sass R objective-c .net sql-server jquery python-3.x angularjs django angular excel regex iphone ajax linux xml pandas vba spring database wordpress string wpf xcode windows bash postgresql oracle multithreading eclipse list firebase algorithm macos forms image scala visual-studio azure bootstrap spring-boot react-native python-2.7 docker performance function winforms matlab powershell apache dataframe api sqlite numpy rest shell selenium flutter dart maven loops qt swing android-studio csv express file class tensorflow sorting codeigniter perl
© 2021 CodesHelper
Advertising Contact us About us
Menu