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From: CDCKAB%EMUVM1.BITNET@cunyvm.cuny.edu ( Karl Brendel)
Newsgroups: comp.lang.pascal
Subject: Re: SEEKING PROBLEMS ABOUT TURBO PASCAL
Message-ID: <25323@adm.brl.mil>
Date: 20 Dec 90 22:00:42 GMT
Sender: news@adm.brl.mil
Lines: 34

In article 9012201616.AA29442@east.gsfc.nasa.gov,
  mecklenburg@storm.dnet.nasa.gov (?Rick) wrote:

>[...deleted...]
>
>why, in some programs, does a write or writeln statement sometimes "fix"
>a program?  For example, the output of a program may be full of garbage, or
>there may be characters missing or whatever, and when I put in a WRITE
>or WRITELN statement, it seems like the TP Gods have waved a magic wand
>or something and presto!.. the program works.
>
>[...deleted...]

Have you ever tried just recompiling without adding the Write or
WriteLn? Writing small programs, I'd bet that you're working within
the IDE and compiling to memory. I'd also bet that on these
occasions you note, that the program works right after you compile
it to and execute it from memory, then you get the garbage on the
second or subsequent run if you don't recompile in the meantime.
That's almost invariably the result of an uninitialized variable:
TPas inits variables (not "typed constants") to 0 when it compiles,
but on a subsequent run (without recompilation), you can get all
kinds of garbage in the variables.

If recompilation doesn't fix the problem, could you post some
_brief_ code illustrating a situation like you're talking about, and
describe your compiling/executing environment (IDE or TPC, etc.)?

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| Karl Brendel                           Centers for Disease Control |
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