GeeCON Prague 2014*
The moose likes Programming Diversions and the fly likes Another Puzzle Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login


JavaRanch » Java Forums » Other » Programming Diversions
Bookmark "Another Puzzle" Watch "Another Puzzle" New topic
Author

Another Puzzle

Sameer Jamal
Ranch Hand

Joined: Feb 16, 2001
Posts: 1870
Suppose x and y are distinct identifiers of type integer. show a simple
context into which either of the code fragments x = 0; y = 1 or y = 1; x= 0 can be substituted so that in most programming languages the resulting substitutions yield different results.
[ February 22, 2006: Message edited by: Sameer Jamal ]
Manish Hatwalne
Ranch Hand

Joined: Sep 22, 2001
Posts: 2578

int x=0;
int y=1;

System.out.println(x-y);
System.out.println(x/y);

- Manish
Vishnu Prakash
Ranch Hand

Joined: Nov 15, 2004
Posts: 1026
x++, y--


Servlet Spec 2.4/ Jsp Spec 2.0/ JSTL Spec 1.1 - JSTL Tag Documentation
Jim Yingst
Wanderer
Sheriff

Joined: Jan 30, 2000
Posts: 18671
Sameer, is the ':' intentional in "x:= 0"? If so, is it intentional that all 3 other expressions do not include a ':'?

I'm thinking maybe the solution is in a for loop, where

is different in effect from

However we need to distinguish between = and == to get this to compile. Most other languages nowadays distinguish between relational operators and assignments - seeing := makes me think of Pascal for example. I don't see a good way to make your text work for any language I'm currently familiar with. Can you confirm the exact syntax, and maybe give a specific languuage it definitely works in?


"I'm not back." - Bill Harding, Twister
Sameer Jamal
Ranch Hand

Joined: Feb 16, 2001
Posts: 1870
Originally posted by Jim Yingst:
Sameer, is the ':' intentional in "x:= 0"? If so, is it intentional that all 3 other expressions do not include a ':'?


No it was not intentional it was just a typing mistake.
There are few languages where comparison operator '==' will not work for eg: VB 6.0

The context can be



In the case that the first code fragment is substituted for the ellipsis, the effect is to set z to 1, while in the second case z gets set to 0.
[ February 22, 2006: Message edited by: Sameer Jamal ]
 
I agree. Here's the link: http://aspose.com/file-tools
 
subject: Another Puzzle