C program part8

1. Declare a pointer called fnc which points to a function that returns an unsigned long.
   unsigned long (*fnc)();
   
   
2. Declare a pointer called pfnc which points to a function that returns a pointer to a structure of type nameAddr.
   struct nameAddr *(*pfnc)();
   
   
3. It is possible for a function to return a character, an integer, and a floating point number. Is it possible for a function to return a structure? Another function?
   No. However, it is possible to return pointers to structures and functions.
   
   
4. What is the difference between an lvalue and an rvalue?
   The lvalue refers to the left-hand side of an assignment expression. It must always evaluate to a memory location. The rvalue represents the right-hand side of an assignment expression; it may have any meaningful combination of variables and constants.
   
   
5. Given the decimal number 27, how would one express it as a hexadecimal number in C?
   0x1B
   
   
6. What is malloc()?
   This function allocates heap storage for dynamic data structures.
   
   
7. What is the difference between malloc() and calloc()?
   The malloc() function allocates raw memory given a size in bytes. On the other hand, calloc() clears the requested memory to zeros before return a pointer to it. (It can also compute the request size given the size of the base data structure and the number of them desired.)
   
   
8. What kind of problems was C designed to solve?
   C was designed to be a "universal" assembly language. It is used for producing system software such as operation systems, compilers/interpreters, device drivers, editors, DBMS's and similar things. It is not as well suited to application programs.
   9.Declare a void pointer
   void *ptr;
   10.Make the pointer aligned to a 4 byte boundary in a efficient manner
   assign the pointer to a long number and the number with 11...1100 add 4 to the number