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From: czgrr <czgrr@my-deja.com>
Subject: Re: differences between C and Ada
Date: 1999/07/22
Message-ID: <7n718n$pet$1@nnrp1.deja.com>#1/1
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Date: 1999-07-22T00:00:00+00:00
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In article <7n6ioe$lkd$1@nnrp1.deja.com>,
  aurelien_ratti@my-deja.com wrote:
> Hello.

Hello.


> What is the difference between C's static variables and Ada's global
> variables ?

One difference is that Ada's global variables have to be, er, global.
That means anything in the package that declares them can access them.
In C++ (and, I assume, C), a static variable can be declared at local
scope, but still has the lifetime of a global.

Another difference is that the C++ compiler will automatically
initialise a static variable to 0 before it is first used. In Ada, you
still have to explicitly initialise it.

A third difference (possibly, I haven't tried it) is that if you have a
C++ class with a static variable, there is only one instance of the
variable regardless of how many objects there are of that class, even
if there are none. In Ada (I think), a global variable in a generic
package exists once per instantiation. Don't know if or how this
translates to C.

I'm sure there's more.

Cheers,
czgrr
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