Difference between Structure and Union

#include <stdio.h>

struct Employee

{

int age;

char Name[50];

char Department[20];

float Salary;

};

union Person

{

int ag;

char Nam[50];

char Departent[20];

float Salar;

};

int main()

{

struct Employee emp1;

union Person Person1;

printf(" The Size of Employee Structure = %d\n", sizeof (emp1) );

printf(" The Size of Person Union = %d\n", sizeof (Person1));

return 0;

}

Call By Value Example

1. #include <stdio.h>
2. #include <conio.h>
3. void change(int num) {
4. printf("Before adding value inside function num=%d \n",num);
5. num=num+100;
6. printf("After adding value inside function num=%d \n", num);
7. }
9. int main() {
10. int x=100;
11. clrscr();
13. printf("Before function call x=%d \n", x);
14. change(x);//passing value in function
15. printf("After function call x=%d \n", x);
17. getch();
18. return 0;
19. }

Call by Reference

1. #include <stdio.h>
2. #include <conio.h>
3. void change(int *num) {
4. printf("Before adding value inside function num=%d \n",*num);
5. (*num) += 100;
6. printf("After adding value inside function num=%d \n", *num);
7. }
9. int main() {
10. int x=100;
11. clrscr();
13. printf("Before function call x=%d \n", x);
14. change(&x);//passing reference in function
15. printf("After function call x=%d \n", x);
17. getch();
18. return 0;
19. }