ecmascript 6 - Is ES6 class extend fully equivalent to Object.assign based extending of an object? -

in other words these 2 different blocks of code equivalent?

es6 class extend based

class child extends parent {     // define subclass } var myinstance = new child(); 

object.assign based

var myinstance = object.assign(new parent(), {    // define subclass } 

in particular use case trying extend (facebook's) flux dispatcher. in examples use object.assign. es6 class extend, worried there subtle differences between 2 should stick object.assign.

no, these code blocks not equivalent

in class inheritance example new constructor makes objects having features parent class.

extending objects via object.assign example of mixins. add properties 1 instance not change future children.

unlike child classes, instance after extension still have constructor property pointing parent. means can't recognize extended child among non-extended, because have same constructor , operator instanceof give same result. can't access overridden methods in child, because lose link it.

as flux's dispatcher in example, can't extend via class inheritance, because there no constructor can provide parent.