Groups > comp.lang.java.programmer > #31106

Re: "null", polymorphism and TCO

From	Joshua Cranmer 🐧 <Pidgeot18@verizon.invalid>
Newsgroups	comp.lang.java.programmer
Subject	Re: "null", polymorphism and TCO
Date	2015-02-10 12:51 -0600
Organization	A noiseless patient Spider
Message-ID	<mbdjti$492$1@dont-email.me> (permalink)
References	<null-20150208185452@ram.dialup.fu-berlin.de> <mcmurtrie-19F4EE.23064308022015@news.sonic.net> <mba2ip$3nr$1@gwaiyur.mb-net.net> <mcmurtrie-338D50.20354409022015@news.sonic.net> <mbcjh4$388$1@gwaiyur.mb-net.net>

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On 2/10/2015 3:37 AM, Marcel Mueller wrote:
> But this does not apply if you assign string constants. E.g.
>
>    String s1 = "foo";
>    s1 == "foo" // might be true
>
> Probably it will be true in most cases since the Java compiler will
> likely not create two instances of the same constant. But I am unsure
> what happens if the two lines are in different java or jar files. I
> think it is simply undefined behavior.

The JLS mandates that all compile-time string constants (this includes 
"fo" + "o") are references to their appropriate interned string, so it's 
guaranteed that "foo" == "foo".intern().

-- 
Beware of bugs in the above code; I have only proved it correct, not 
tried it. -- Donald E. Knuth

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Thread

Re: "null", polymorphism and TCO Kevin McMurtrie <mcmurtrie@pixelmemory.us> - 2015-02-08 23:06 -0800
  Re: "null", polymorphism and TCO Marcel Mueller <news.5.maazl@spamgourmet.org> - 2015-02-09 11:36 +0100
    Re: "null", polymorphism and TCO Kevin McMurtrie <mcmurtrie@pixelmemory.us> - 2015-02-09 20:35 -0800
      Re: "null", polymorphism and TCO Marcel Mueller <news.5.maazl@spamgourmet.org> - 2015-02-10 10:37 +0100
        Re: "null", polymorphism and TCO Joshua Cranmer 🐧 <Pidgeot18@verizon.invalid> - 2015-02-10 12:51 -0600

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