Programming Puzzle

[Sameer Jamal]

Exhibit a simple context into which either of the phrases (1 + 2) or (2 +
1) can be substituted so that in essentially all programming languages the resulting substitutions yield different results.

[Arjunkumar Shastry]

I read this more than 5 times.But didn't understand.Can you explain in simple words?

[Sameer Jamal]

Suppose there are two phrases (1+2) or (2+1) which can be substituted, we have to show a programming statement(algorithm) so that if we substitute one phrase with other it will give the different output in different programming languages.
[ February 21, 2006: Message edited by: Sameer Jamal ]

[Jim Yingst]

"...in essentially all programming languages" - errr, that's pretty open-ended. My examples will be Java-specific, though similar equivalents exist in other languages.

----

Trivial solution:

System.out.println("(1+2)");

has different output than

System.out.println("(2+1)");

----

Slightly more interesting:

String[] parts = str.split("(1+2)");

Matches differently than

String[] parts = str.split("(2+1)");

----

Is that the sort of thing you mean?

[Reid M. Pinchback]

For any (programming or mathematical) language that allows you to define "+" you can make this trivially true, just define "+" to be some non-commutative operation. (1+2)==(1+2) is assuming commutativity, so all you need to do is pick contexts where commutativity doesn't hold.

[Sameer Jamal]

Originally posted by Jim Yingst:
"...in essentially all programming languages" - errr, that's pretty open-ended. My examples will be Java-specific, though similar equivalents exist in other languages.

----

Trivial solution:

System.out.println("(1+2)");

has different output than

System.out.println("(2+1)");

----

Slightly more interesting:

String[] parts = str.split("(1+2)");

Matches differently than

String[] parts = str.split("(2+1)");

----

Is that the sort of thing you mean?

Nobody can beat Jim, wait for my next puzzle.
[ February 21, 2006: Message edited by: Sameer Jamal ]

[Mani Ram]

Originally posted by Sameer Jamal:


Nobody can beat Jim, wait for my next puzzle.

[ February 21, 2006: Message edited by: Sameer Jamal ]

I thought exactly the same thing (the System.out.println solution, not the split one), but never posted the solution, because it looked too too stupid to me