Can a JavaScript object have a prototype chain, but also be a function?

Question

function a () {
    return \"foo\";
}

a.b = function () {
    return \"bar\";
}

function c () { };
c.prototype = a;

var d = new c();
d.b(); // returns \"bar\"
d()         


        

Answer 1

Based on a discussion on meta about a similar question I'm posting this answer here based on @alexander-mills original

---

This can now be done in a standards compliant way

First create an object which inherits Function

const obj = Object.create(Function.prototype);  // Ensures availability of call, apply ext

Then add you custom methods and properties to obj

Next declare the function

const f = function(){
    // Hello, World!
};

And set obj as the prototype of f

Object.setPrototypeOf(f,obj);

Demonstraction

const obj = Object.create(Function.prototype);

// Define an 'answer' method on 'obj'
obj.answer = function() {
  // Call this object
  this.call(); // Logs 'Hello, World'
  console.log('The ultimate answer is 42');
}

const f = function() {
  // Standard example
  console.log('Hello, World');
};

Object.setPrototypeOf(f, obj);

// 'f' is now an object with an 'answer' method
f.answer();
// But is still a callable function
f();