Function instead of object in setState?

Question

React

I came across an article on React, which describes the benefits of changing state with a function call.
There is a structure like this:

submit(){
   this.setState(function(prevState, props){
      return {showForm: !prevState.showForm}
   });
}

Please explain, what is the use of the props parameter, which is not used? I'm more of a mathematician than a proger, I don't understand such jokes

Answer 1

The presence of a function argument does not force it to be used. This is done so that, if desired, you can refer to the properties.