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From: seth@ctr.columbia.edu (Seth Robertson)
Newsgroups: comp.lang.c
Subject: sizeof(array)
Message-ID: <1989Aug22.024808.17913@ctr.columbia.edu>
Date: 22 Aug 89 02:48:08 GMT
Reply-To: seth@ctr.columbia.edu (Seth Robertson)
Organization: Columbia University Center for Telecommunications Research
Lines: 52


Hi.

I have a problem in that when I pass an array, it loses track of its size.

ex.
------------------------------------------------------------------
unsigned long testcode[] =
{
  3422617600,
  3422752768,
  513998896,
  2684354560,
  0 };

main()
{
  int size = sizeof(testcode) / sizeof(testcode[0]);

  printit(testcode);
  printf("Loading %d %d %d\n",size,sizeof(testcode),sizeof(testcode[0]));
}


printit(code)
unsigned long code[];
{
  int size = sizeof(code) / sizeof(code[0]);

  printf("Loading %d %d %d\n",size,sizeof(code),sizeof(code[0]));
}
----------------------------------------------------------------------
Output:

Loading 1 4 4		<-- Incorrect
Loading 5 20 4		<-- Correct


I guess I understand what it is does (only passing the address, not any
additional information), but how do I get it to do what I want?


In case you are wondering, yes, there are good reasons for making
`printit' a subroutine, for passing code as a parameter instead of
explicitly naming testcode, and for making testcode a global
automatically initialized variable (variable only at compile time,
obviously) sized array.


-- 
                                        -Seth Robertson
                                         seth@ctr.columbia.edu