Newbie questions about variables

kunal chavan kunal@deeproot.co.in
Sat Sep 27 01:26:00 GMT 2003


Hi Andre

   If you allocate memmory to theString (should be pointer to string not 
array of pointer's in your case)
   in your theFunction from heap (using malloc) then certainly it will 
eat up your available heap
   if you do not free it at each subsequent call and the results may be 
unpredictable.
   
   On other hand if you declare string like "char theString[256] 
"(static memmory allocation) in
   your funtion or allocate memmory using alloca " char *theString = 
alloca(StringLen) "
   memmory will be allocated in functions stack and the stack will be 
flushed as soon as
   control returns to main function.

    Kunal.   

Andre Kirchner wrote:

>Hi,
>
>what would happen if I had a function which creates a
>string, and a for loop in the main function that
>executes this function 100 times, will it create 100
>theString variables which will just be using memory
>space, or each time my program exists
>theFunction theString variable will be erased from the
>computer's memory?
>Is there any command to destroy a variable, and free
>the memory space it was using if I need?
>
>Thanks
>
>Andre
>
>void theFunction( const char * newString )
>{
>  char * theString[ 256 ];
>
>
>  strcpy( theString, newString ); <---- This is syntax error
>

>
>  printf( "%s\n", theString );
>}
>
>void main()
>{
>  int counter;
>  char theLine[ 256 ];
>
>  for( counter = 0; counter< 100; counter++ )
>  {
>    sprintf( theLine, "%03d\n", counter );
>    theFunction( theLine );
>  }
>}
>
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