JavaScript - Variable/object as string and function at the same time

Question

Is it possible to create variable/object, which returns string and function at the same time?

> a
'Hello World'
> a()
2018-07-13T13:45:10.967Z

I've seen article about default methods of JavaScript objects, but I couldn't find it now.

I think it should be something like:

// Pseudo code
const a = {
    toString: "Hello World",
    function: () => new Date(),
};

@aquaballin did you mean do I test my _"code"_? :) Sure, but results is returned with: `a.toString` and `a.function()`. I'd like get values with `a` and `a()`. — Mateusz Jagiełło, Jul 13 '18 at 13:51
You need to define a function a and then add a toString method to that function. — Axnyff, Jul 13 '18 at 13:57
I am 100% sure that what you are trying to do is not possible, variables in Js can indeed assume different types, but you have to explicitly say that. — Bruno Braga, Jul 13 '18 at 13:59
Or possibly by creating a function first and then overriding toString of Function.prototype somehow to execute another function/statement that returns desired string. — Rikin, Jul 13 '18 at 14:16
No, it's not possible for a value to be a function and a primitive string at the same time. What do you need this for? — Bergi, Jul 13 '18 at 17:45
If this were possible I wonder what would print `console.log(typeof a)`; — lealceldeiro, Jul 13 '18 at 18:33

Nelson Teixeira · Answer 1 · 2018-07-13T17:55:12.663

1

AFAIU this is only possible if, when you need the string, you use the variable in a way to enable explicit or implicit conversion, like this:

const a = function () {
  return new Date()
};
a.toString = function() {
  return "Hello world";
}

console.log('' + a);
console.log(String(a));
console.log(a());

edited Jul 13 '18 at 17:55

answered Jul 13 '18 at 14:54

Nelson Teixeira

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This only works with `console.log(String(a))`. Logging `a` alone will log the object. – Bergi Jul 13 '18 at 17:44
@bergi thanks for pointing my error. I was led to believe it was ok because in SO's snippet if you run the code the output of `console.log(a)` outputs `Hello World`. As I tried outside of it I saw you were right. I corrected my answer. – Nelson Teixeira Jul 13 '18 at 17:56

JavaScript - Variable/object as string and function at the same time

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