Does ECMA6 allow prototype syntax as a best practice in JavaScript?

Example

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes

JavaScript classes are introduced in ECMAScript 6 and are syntactic sugar over the existing JavaScript prototype-based framework. The class does not introduce a new object-oriented inheritance model for JavaScript. JS classes provide a much simpler, more straightforward syntax for creating objects and working with inheritance.

Does this mean that I should stop using the language term prototype

in my development when ECMA6 is final and used in this way using new syntactic sugar. I believe they are the same as others (from the same page):

// unnamed
var Polygon = class {
  constructor(height, width) {
    this.height = height;
    this.width = width;
  }
};

// named
var Polygon = class Polygon {
  constructor(height, width) {
    this.height = height;
    this.width = width;
  }
};

      

        
        
        
      

    

On the other hand, I can see it,

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/Method_definitions

var obj = {
  foo() {},
  bar() {}
};

      

        
        
        
      

    

How does it all fit together? What should I do with var myObj

? Can it have a constructor and methods, foo()

and bar()

like other languages? Is this acceptable?

var myObj = class myObj {
 contructor(height, width){
     this.height=height;
     this.width=width;
 },
  foo(this.height) {alert('the height is ' + this.height)},
  bar(this.height, this.width) {
      alert('the width is ' + this.width);
      var something = this.height + 5;
      alert('the height is : ' + something);

  }
};

var determine_something = new myObj(50,60);
determine_something.bar;
determine_something.foo;

      

        
        
        
      

    

(This did not work in the ECMA6 sandbox that I tried)

This gives no errors, but this.height

is undefined:

var myObj = class {
 contructor(height, width){
     this.height=height;
     this.width=width;
 }
  foo() {
    alert('the height is ' + this.height);
  }

};

var determine_something = new myObj(50,60);
determine_something.foo();

      

        
        
        
      

    

EDIT: If I am not using prototype

and I want to add a new method, how do I do it with the new syntax?