Re: Bizarre import weirdness

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#298

From: John R. Antley
Date: Tue, 04 Dec 2001 23:18

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Hi Ron,

Jon is right.

The 'import <package>.*' statement does nothing AT RUN TIME.  This makes the
die-hard Java enthusiasts very happy [no conditional compilation].

At COMPILE TIME is a different story...  Per your example, the compiler doesn't
know which Date object you mean.  It merely ASSUMES what imports have told it are
true.  If not [say, you change a method, and somehow its .class doesn't get
recompiled, you have an old .JAR which doesn't match an import, or whatever], you
get a RUNTIME EXCEPTION [when the .class bytecodes are being interpreted].

There's a major difference between the old, compiled languages [Modern Basic
(including VB), Pascal, C, C++, etc.] vs. the newer interpreted bytecode/script
kind of theory [Java, C# (Java ripoff), Python, Perl, JavaScript].  The former
rely on COMPILE TIME LINKING and the latter on RUN TIME CLASS RESOLUTION.  Both
have distinct advantages beyond the scope of this thread.

Sorry; I didn't mean to insult your intelligence.  The discussion just turned on
a light bulb for and old C/C++ jockey I thought I'd try to articulate.

HTH,
JR

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From: "John R. Antley" <jrantley@mindspring.com>
Newsgroups: comp.lang.java.programmer,borland.public.jbuilder.ide
Subject: Re: Bizarre import weirdness
Date: Tue, 04 Dec 2001 16:18:59 -0700
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