-D system properties option

[Henning Ludeke]

Hi

I would like to know what does the 'D' denote?

I know how to use it, but I would just like to know if the D stands for anything specific.

Thanks,

Henning

[Ankit Garg]

You can find information about the different options of java command here. -D is used to set system properties, these properties can be used by your application or by the JVM. You can find some more details here...

[Jesper de Jong]

Welcome to JavaRanch.

Maybe the "D" stands for "Define". But that's just a guess. The documentation doesn't say why the letter "D" is used or what it stands for.

[Henning Ludeke]

It's driving me crazy. I want to know why it is a 'D'

Maybe we should email Dr. Gosling

[Jesper de Jong]

I don't know if you know C or C++, but in those languages you have a precompiler. You can use #define in a source file to define for example constants etc., like this:

#include <stdio.h>

#define MAGIC_NUMBER 23

int main(int argc, char* argv[]) {
    printf("The magic number is %d\n", MAGIC_NUMBER);
}

Some C or C++ compilers allow you to define constants on the command line, when you invoke the compiler. Like this:

gcc -DMAGIC_NUMBER=23 example.c -o example

I guess the "-D" in Java has a similar function (although Java doesn't have a preprocessor and you're not defining compile-time constants with it).

If you're still not satisfied with the answer, you can indeed try asking the big boss...

[Henning Ludeke]

Jesper - that makes sense.

Java is the first language that I'm delving into -
I guess if I had experience with C++ I would've been familiar with 'define' - it makes sense.

No more ...

Thanks Jesper

[David Newton]

I'd recommend not getting too hung up on minutiae like this very often, or you'll go mad.

[Satya Maheshwari]

David Newton wrote:I'd recommend not getting too hung up on minutiae like this very often, or you'll go mad.

[Henning Ludeke]

Thanks everybody