What will be the output of the following C program?
void swap(int *x, int *y) {
int temp = *x;
*x = *y;
*y = temp;
}
int main() {
int a = 10, b = 20;
swap(&a, &b);
printf("%d %d", a, b);
return 0;
}
Options
-
A.
10 20
-
B.
20 10
-
C.
10 10
-
D.
More than one of the above
-
E.
None of the above
Correct Answer (Detailed Explanation is Below)
B.
20 10
Detailed Explanation
Correct Answer: 20 10
The addresses of a and b are passed to the function using &a and &b.
Inside the function, *x and *y access the actual values of a and b. Therefore, changing *x and *y changes the original variables.
Initially, a = 10 and b = 20. After swapping, a becomes 20 and b becomes 10.
Exam point: Passing addresses to a function allows the function to modify the original variables. This is commonly called passing by address using pointers.
