class expression

"use strict";
var Foo = class {}; //   
var Foo = class {}; //   

typeof Foo; //  "function"
typeof class {}; //  "function"

Foo instanceof Object; // true
Foo instanceof Function; // true
class Foo {} // Throws TypeError, doesn't allow re-declaration

var Foo = class {
  constructor() {}
  bar() {
    return "Hello World!";
  }
};

var instance = new Foo();
instance.bar(); // "Hello World!"
Foo.name; // "Foo"

var Foo = class NamedFoo {
  constructor() {}
  whoIsThere() {
    return NamedFoo.name;
  }
};
var bar = new Foo();
bar.whoIsThere(); // "NamedFoo"
NamedFoo.name; // ReferenceError: NamedFoo is not defined
Foo.name; // "NamedFoo"