pass a pointer-to-pointer, or return a pointer? Post: 302273792

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Top Forums Programming pass a pointer-to-pointer, or return a pointer? Post 302273792 by aaronwong on Monday 5th of January 2009 11:39:22 PM

01-06-2009

Registered User

pass a pointer-to-pointer, or return a pointer?

If one wants to get a start address of a array or a string or a block of memory via a function, there are at least two methods to achieve it:
(1) one is to pass a pointer-to-pointer parameter, like:

Code:

int my_malloc(int size, char **pmem)
{
      *pmem=(char *)malloc(size);
      if(*pmem==NULL) {
             return NOK;
      }
      return OK;
}
int main()
{
       char *my_pmem;
       if(my_malloc(64, &my_pmem)==OK){
        ...
       } else {
       ...
       }
}

(2)the other is to return a pointer, like:

Code:

void * my_malloc(int size)
{
       void * pmem;
       pmem=malloc(size);
       return pmem;
}
int main()
{
      char *my_pmem;
      my_pmem=(char *)my_malloc(64);
      if(my_pmem==NULL) {
           ...
      } else {
           ...
      }
}

Could anyone tell the difference(advantages and disadvantages )about those two methods ？

Thanks in advance !

Last edited by Franklin52; 01-06-2009 at 07:17 AM.. Reason: adding code tags

aaronwong

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