Javascript String Object V.S. just string

Question

OK, first, i'm not going to seek a method to convert the Object to String.

but i'm facing a problem like this:

String.prototype.foo = function() {
 return this;
};
var rawString = "abcde";
var fooString = "abcde".foo();
console.log(typeof(rawString) + ': ', rawString);
console.log(typeof(fooString) + ': ', fooString);

or jsfiddle you preferred.

also, a screenshot is attached:

the strange thing in Javascript.

---

as you can see, i did almost nothing in the prototype method foo, i just return this.

but the result of typeof are totally different

Why is this? how can i just return abcde rather thant {0: "a"...} ?

Thanks!

• Crescent Fresh: possible duplicate of Javascript WTF: a String.prototype's "this" doesn't return a string?
• Ya Zhuang: @CrescentFresh oops, you're right. i tried to search, but i didn't make it. sorry for the duplicate question.

Answer 1

The this references the String Object, so you need to return it like

return this.toString();

which in turn, creates the primitive string version and returns it.

• Ya Zhuang: great! thanks!! but feel so strange to write the "string".toString() .. LOL, odd javascript.
• ted: @bitsMix, it's an object oriented language