Is Function.prototype the only function without a prototype property?

Question

Is Function.prototype the only function without a prototype property?

Why is the property absent instead of having a prototype property with a value of null.

document.write(Object.getOwnPropertyNames(Function.prototype));

Edit: presumably the prototype property is elided because it does not have a [[Construct]] internal method (it is not a constructor).

• elclanrs: I don't know if the "why" is relevant, it just is, but here's what the spec says ecma-international.org/ecma-262/7.0/…
• Jaromanda X: Perhaps the NOTE in that section explains why Function.prototype is a function at all
• Oriol: This was part of Function.prototype is a function, but probably that should have been split into multiple questions, so I don't think this should be closed as duplicate.

Answer 1

Only constructors have the prototype property:

Function instances that can be used as a constructor have a prototype property.

There are multiple examples of non-constructor functions apart from Function.prototype, such as

• Methods in Math object:

  typeof Math.pow; // "function"
  'prototype' in Math.pow; // false
  

• Some host objects:

  typeof document.createElement('object'); // "function"
  'prototype' in document.createElement('object'); // false
  

• In ES6, arrow functions:

  typeof (x => x * x); // "function"
  'prototype' in (x => x * x); // false
  

• Ben Aston: Do you know of any exotic non-constructor functions with the prototype own property as the spec appears to leave room for? (section 9.3 para 6: ecma-international.org/ecma-262/7.0/…)
• Oriol: @BenAston I don't know any native example. I don't think there is any point in having a prototype property if the function is not a constructor.

Answer 2

Ah, just found that section 9.3 para 6 says:

Built-in functions that are not constructors do not have a prototype property unless otherwise specified in the description of a particular function.

All "normal" functions have the [[Construct]] internal method (section 9.2.3):

If functionKind is "normal", let needsConstruct be true.

Exotic built-in functions may or may not have the [[Construct]] internal method and if they do not, then they do not have the prototype property, "unless otherwise specified".