So heres a simple c++ function what it does it take an array of characters as its argument and a integer n and then creates a new character array with only n elements of the array.

char * cutString(char * ch , int n){

  char * p = new char[n];
  int i ;
  for(i = 0 ; i < n ; i++)
         p[i] = ch[i];
  while(i <= n ){
    p[i++] = '\0';
  }
  return p ;

}

this works just fine but if I change char * p = new char[n]; to char p[n]; I see funny characters what happens ? What difference does the former make also p is a temporary variable then how does the function returns it alright ?