What is the difference between the description of methods in classes?

Question

React

Can you tell me what's the difference?
How will this stuff behave in ES6 AND ES7/NEXT
func1 and func2 have automatic this binding under the hood and will always be bound to Todo? is it a portotype or not?
func3 doesn't have any magic binding, it's a class prototype.
Did I understand everything correctly and are there any other differences?

class Todo extends Component {
state = {};

  const func0= (id) => {
return 1+1;
  };

  func1= (id) => {
  };
 
const func2= ({ username }) => <p>The logged in user is: {username}</p>;
  func3() {
  return 1;
  }	
}

Answer 1

You can see what your code turns into in babel repl (do not forget to check the react box in the left menu)
you cannot write const inside the class
func1 will have this referring to Todo
func3 - will not