Domenic Denicola domenic at
Tue Aug 26 09:26:48 PDT 2014

`x+''` produces different results than ToString when `x = { toString() { return '5'; }, valueOf() { return 10; } }`
From: es-discuss <es-discuss-bounces at> on behalf of Brendan Eich <brendan at>
Sent: Tuesday, August 26, 2014 12:14
To: Claude Pache; Jeff Walden
Cc: Erik Arvidsson; es-discuss at
Subject: Re: String(symbol)

Claude Pache wrote:
> Personally, I use the following expression in order to coerce a variable to a string:
>       var obj = this + ''
> and its in-place variant:
>       x += ''
> I think it'll continue to work in ES6.

Agreed, this is the correct-and-most-concise way to do it. It should
throw on symbols, that's important.

Having String(sym) not throw is a win for other reasons Arv identified,
but using String(any) to invoke ToString is verbose and fragile, because
String could be rebound :-P. Use +'' if you want ToString in the
language, I say.

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