What is the main difference between STRUCTURE and UNION?
- 13 Answers
- 187340 Views
- HCL, I also Faced
- E-Mail Answers
Answer Posted / anil kumar nahak
1.)A union is a way of providing an alternate way of
describing the same memory area. In this way, you could
have a struct that contains a union, so that the "static",
or similar portion of the data is described first, and the
portion that changes is described by the union. The idea of
a union could be handled in a different way by having 2
different structs defined, and making a pointer to each
kind of struct. The pointer to struct "a" could be assigned
to the value of a buffer, and the pointer to struct "b"
could be assigned to the same buffer, but now a->somefield
and b->someotherfield are both located in the same buffer.
That is the idea behind a union. It gives different ways to
break down the same buffer area.
2.)The difference between structure and union in c are: 1.
union allocates the memory equal to the maximum memory
required by the member of the union but structure allocates
the memory equal to the total memory required by the
members. 2. In union, one block is used by all the member
of the union but in case of structure, each member have
their own memory space
3.)Detailed Example:
struct foo
{
char c;
long l;
char *p;
};
union bar
{
char c;
long l;
char *p;
};
A struct foo contains all of the elements c, l, and p. Each
element is
separate and distinct.
A union bar contains only one of the elements c, l, and p
at any given
time. Each element is stored in the same memory location
(well, they all
start at the same memory location), and you can only refer
to the element
which was last stored. (ie: after "barptr->c = 2;" you
cannot reference
any of the other elements, such as "barptr->p" without
invoking undefined
behavior.)
| Is This Answer Correct ? | 42 Yes | 29 No |
Post New Answer View All Answers
What is the difference between proc means and proc tabulate ? explain with a simple example when you have to use means or tabulate?
How do you verify if the two sentences/phrases input is an anagram using predefined functions in string.h and by using arrays?
What is the match merge ? compare data step match merge with proc sql merge - how many types are there ? data step vs proc sql
Can you send Code for Run Length Encoding Of BMP Image in C Language in linux(i.e Compression and Decompression) ?
write a c program to input initial & final time in the format hh:mm and find the time intervel between them? Ex inputs are initial 06:30 final 00:05 and 23:22 final 22.30
I need your help, i need a Turbo C code for this problem.. hope u'll help me guys.? Your program will have a 3x3 array. The user will input the sum of each row and each column. Then the user will input 3 values and store them anywhere, or any location or index, temporarily in the array. Your program will supply the remaining six (6) values and determine the exact location of each value in the array. Example: Input: Sum of row 1: 6 Sum of row 2: 15 Sum of row 3: 24 Sum of column 1: 12 Sum of column 2: 15 Sum of column 3: 18 Value 1: 3 Value 2: 5 Value 3: 6 Output: Sum of Row 1 2 3 6 4 5 6 15 7 8 9 24 Sum of Column 12 15 18 Note: Your program will not necessary sort the walues in the array Thanks..
How can you relate the function with the structure? Explain with an appropriate example.
Write a program to model an exploding firecracker in the xy plane using a particle system
How to palindrom string in c language?
could you please send the program code for multiplying sparse matrix in c????
A program that will create a movie seat reservation. The program will display the summary seats and its status. The user will be ask what seat no. to be reserved, then it will go back again to the summary to display the updated seat status. If the seat no. is already reserved then it will prompt an error message. And also if the input seat no is out of range then it will also prompt an error message. The program is continuously running. Termination of the program will depends on how the programmer will apply. Sample output: Movie Seats Reservation Summary of Seats: Seat 1: Available Seat 2: Available Seat 3: Available Seat 4: Available Seat 5: Available Enter seat no. (Press 0 to terminate Or the assigned seat capacity) : 1 Movie Seats Reservation Summary of Seats: Seat 1: Reserve Seat 2: Available Seat 3: Available Seat 4: Available Seat 5: Available Enter seat no. (Press 0 to terminate Or the assigned seat capacity) : 6 The Seat no. is out of range! Movie Seats Reservation Summary of Seats: Seat 1: Reserve Seat 2: Available Seat 3: Available Seat 4: Available Seat 5: Available Enter seat no. (Press 0 to terminate Or the assigned seat capacity) : 1 The Seat no. is already reserved! Movie Seats Reservation Summary of Seats: Seat 1: Reserve Seat 2: Available Seat 3: Available Seat 4: Available Seat 5: Available Enter seat no. (Press 0 to terminate Or the assigned seat capacity) : 0 GoodBye... Thank You!!!
What is full form of PEPSI
can you use proc sql to manpulate a data set or would u prefer to use proc report ? if so why ? make up an example and explain in detail
why do you use macros? Explain a situation where you had to incorporate macros in your proc report? use a simple instream data example with code ?
Write a Program in 'C' To Insert a Unique Number Only. (Hint: Just Like a Primary Key Numbers In Database.) Please Some One Suggest Me a Better Solution for This question ??
