javascript - Check if class constructor extends another class -

this question has answer here:

• check if constructor inherits in es6 2 answers

how can check if class constructor extends class, without constructing object? ie constructor reference.

example

class {  }  class b extends {  }  var b = b;  if(typeof b === b) 

you can check of instanceof below.

class {    }    class b extends {    }    class c {    }      console.log(b.prototype instanceof a);  console.log(c.prototype instanceof a);    // instance  var b = new b();    console.log(b instanceof b);  console.log(b instanceof a);  console.log(b instanceof c);