JavaScript - Why can't I add new attributes to a “string” object?

Question

I\'ve experimented with JavaScript and noticed this strange thing:

var s = \"hello world!\";
s.x = 5;
console.log(s.x); //undefined

Every t

Answer 1

Skilldrick’s answer explains why it doesn’t work and therefore answers your question.

As a side note, it is possible to do this:

var s = {
  toString: function() { return "hello world!"; }
};
s.x = 5;
console.log(s.x); // 5
console.log('result: ' + s); // "result: hello world!";
console.log(String(s)); // "hello world!";