What is toLocaleString()?

Question

According to this MDN page, toLocaleString is about converting dates. However, Chrome exposes the function on more than strings. For example:

a = function () {};
a.toLocaleString();  // "function () {}"

What is the toLocaleString? Why is it exposed, for example, on the empty function?

Answer 1

It's also available on Object.prototype, so indirectly on pretty much anything.

For Chrome, you can look at V8's implementation, which doesn't do anything fancy:

function ObjectToLocaleString() {
  if (IS_NULL_OR_UNDEFINED(this) && !IS_UNDETECTABLE(this)) {
    throw MakeTypeError("called_on_null_or_undefined",
                        ["Object.prototype.toLocaleString"]);
  }
  return this.toString();  // <-- just calls toString
}