GATE Overflow Test Series | Programming | Test 1 | Question: 29

Question

What will be the output of the following C program?

#include<stdio.h>
void foo(int a, int *p1, int **p2)
{
    **p2 = 5;
    *p1 = 6;
    a = 7;
}
int main()
{
    int a, *p1 = &a, **p2 = &p1;
    a = 9;
    foo(a, p1, p2);
    printf("%d", a);
}

 

Answer 1

In C, parameters are passed by value.

Here, p1 is having address of a and p2 is having address of p1.

Inside foo, **p2=5 makes the value of a = 5.

*p1 = 6 further changes it to 6.

But a = 7 won't affect the 'a' inside the main as it is a local copy.

Correct Answer: 6.