Re: one interview question, 17 lines in java, 3 lines in ruby.

From:
 Daniel Pitts <googlegroupie@coloraura.com>
Newsgroups:
comp.lang.java.programmer
Date:
Fri, 21 Sep 2007 00:13:18 -0000
Message-ID:
<1190333598.372818.187200@q5g2000prf.googlegroups.com>
On Sep 20, 11:59 am, Lew <l...@lewscanon.com> wrote:

Piotr Kobzda wrote:

Well, 161 chars:
class C{static{String s="27 0",g=" A";for(int
i=1;i<27;s+=i++%10,g+='A')System.out.println(i+g.replace('A',(char)(64+i)));System.out.println(s);System.exit(0);}}

Lew wrote:

How does this class get loaded into the JVM?

Daniel Pitts wrote:

java C

This will first load the class C, which executes the static
initializer. The initializer exits the JVM before it has a chance to
look for the main method, so no exception occurs.


What a great hack!

--
Lew


Here's a better one: I got the code down to 139 characters...
enum C{a;{String g=" ",s="27 0";for(int i=1;i<28;s+=i++%10,g
+=0)System.out.println(i>26?s:i+g.replace('0',(char)
(64+i)));System.exit(0);}}

The trick to this one:

enums create one instance of their children during their static
initialization. This of course, calls the non-static initializer of
the super class, and then the child class.

So, as far as I know, the following is the smallest (source) non-
erroring program
enum C{a;{System.exit(0);}}
taking up only 28 chars, it is smaller than the other version by 5
chars:
class C{static{System.exit(0);}}
which takes 33 chars, and is itself *13* chars shorter than the
"standard" approach:
class C{public static void main(String[]a){}}
at a whopping 46 chars.

:-)

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