RE: MIA, Ask an Expert: pacman ghosts

["Alain Tougas" <alain@xxxxxxx>]

Hi!

If your program is similar to the "SnacMan sample", you have an OnTouch rule
that says:
WhoAreYou
and such procedure on the Procedures tab:

to whoareyou
ifelse touchedturtle = "ghost
   [zapped]
   [eat]
setstrength strength + 1000
end

The problem is, only ONE ghost can be called ghost.

My proposal goes like this:

Name your ghosts: ghost1 ghost2 ghost3 etc.

Then the procedure should check if the "beginning" of the name of the
touched turtle is "ghost". In other words, TRIM the number at the end of the
turtle's name and check if the remaining = ghost.

to whoareyou
ifelse (butlast touchedturtle) = "ghost
   [zapped]
   [eat]
setstrength strength + 1000
end

The trick is: butlast "ghost1 is "ghost. Butlast "ghost2 is also "ghost. In
other words, (butlast touchedturtle) = "ghost will be true for any turtle
that has a name made of GHOST plus one character.

You need the parenthesis because without them
butlast touchedturtle = "ghost
MicroWorlds will do touchedturtle = "ghost
which will report false, and butlast will report the butlast of the word
FALSE, which is FALS. Not what you want.


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from: Todd <Todd.Whitefleet@xxxxxxxxxxxxx>
date: Thu Oct  4 12:29:42 2007
platform: PC
version: MicroWorlds Ex

I have a pacman type turle that loses a life when it hits a
floating ghost. How do I get it to lose a life when there
is more than one ghost? It eats them like the food pellets
instead of losing a life.