Write a program that always outputs “2012” - even if it's modified!

Question

This idea is not mine, though I don't know where it originated. I once met it in a programming contest very long ago (1998, if I remember correctly). The task is to write a program in your favorite language that outputs 2012 and only 2012. The catch is that the program must still output 2012 after any one of its characters is modified. The modification can be either insertion, deletion or replacement. Of course, the modification will be such that the program is still syntactically valid.

Since I don't know all the programming languages, I have to ask the audience to help me and test the answers submitted.

Added: Many have commented that my definition of acceptable modifications is too vague. Here's my second attempt: The allowed modifications will leave your program syntactically valid and will not cause it to crash. There, I think that should cover all the compile-time, link-time and run-time errors. Though I'm sure that there will be some odd edge case in some language anyway, so when that comes up we'll look at it individually.

Answer 1

Tcl, 55 chars.

if {[set a {puts 2012}]=={puts 2012}} $a {
puts 2012
#}

Check if the code is unmodified, then execute it, or print 2012.
I consider accessing a undefined variable as syntax error.

Tcl, 138 Characters

set a {set a {$a};if {\$a=={$a}} {puts 2012}};if {[info ex a]&&$a=={set a {$a};if {\$a=={$a}} {puts 2012}}} [subst -noc $a] {
puts 2012
#}

Ok, this is a quine variant: either the code is unmodified, then execute it, or simply print 2012

The last line is a little bit special: It is a comment, but the } closes the brace.

Answer 2

Python 40 characters

a='2012';print(2012
)if a!='2012'else a

I don't think it's possible to get it any smaller with this approach in python.

edit: added 4 quotes to counter effects of -a on the end edit: removed space

Answer 3

Python (45 49 52 chars)

nn='2012'
if nn=='2012':
    print nn
else:
    print 2012

Answer 4

Lua, 33 36

xx=2012
print(xx==2012
and xx or 2012)

Answer 5

I write it in Java

try{
    //your code
) catch(Exception e) {
//eat exception
} finally{
    System.out.println("2012");
}

Answer 6

Python - 50 41 40 41 chars

x='2012'
if x=='2012': print x
else: print '2012'

exec('cHJpbnQgMjAxMg=='.decode('base64'))

exec('x\x9c+(\xca\xcc+Q0204\x02\x00\x13\xfa\x03\x13'.decode('zip')

)

Yes, I know you can modify 'print x' into "print 1" or something similar, but not sure how to beat that..

Answer 7

Ruby (57 36)

EDIT And another one in 36 chars.

p((x,y='2012','2012';x=='2012'?x:y)) 

I guess using strings is pretty failsafe because that minus thing doesn't work any more.

---

EDIT next try (36 chars) [never mind, adding a - after p results in -2012]

p [2012,2012].find(2012).first||2012

---

This one will only work this year, but also for similar contests in the future :) (15.chars)

p Time.now.year

Note that this substitution is also working:

p Time.new.year

---

57 chars. If you count the newlines, too it is 76 chars, though.

p( 
#
#
#
#
#
#
#
#
#
#
__LINE__.to_s.prepend(
#
#
#
#
#
#
#
__LINE__.to_s))