Return a variable like char *?

lilishon

Pass the actual parameter to this n

海里的浪

How to pass out this parameter?

reekee_max

void fun (char * in, char * out),
If you want to allocate space for out in fun, it is very dangerous, because you don't know when to release him.

It depends on what function your fun wants to achieve.
You can do this if you just want to add the most characters.

void fun (char * in, char * out)
{
  int i = strlen (in);
  int i1 = strlen (out);
  char * szBuff = new char [i1 + 1];
  strcpy (szBuff, out);
  if (out) {delete out; out = NULL;}
  out = new char [i + i1 + 1];
  sprintf (out, "% s% s", szBuff, in);
  delete [] szBuff;
}

void main ()
{
  char * out = new char [6];
  strcpy (out, "Hello");
  fun ("LZ", out);
  printf ("% s\n", out);
  delete [] out;
}

jyq1215

Call a function, pass the address
The pointer is declared before calling the function, and the memory is applied
After calling this function, release it and set it to empty

Otherwise there will be danger