C Programming - Functions - Discussion

Discussion Forum : Functions - Find Output of Program (Q.No. 19)
19.
What will be the output of the program?
#include<stdio.h>

int fun(int i)
{
    i++;
    return i;
}

int main()
{
    int fun(int);
    int i=3;
    fun(i=fun(fun(i)));
    printf("%d\n", i);
    return 0;
}
5
4
Error
Garbage value
Answer: Option
Explanation:

Step 1: int fun(int); This is prototype of function fun(). It tells the compiler that the function fun() accept one integer parameter and returns an integer value.

Step 2: int i=3; The variable i is declared as an integer type and initialized to value 3.

Step 3: fun(i=fun(fun(i)));. The function fun(i) increements the value of i by 1(one) and return it.

Lets go step by step,

=> fun(i) becomes fun(3) is called and it returns 4.

=> i = fun(fun(i)) becomes i = fun(4) is called and it returns 5 and stored in variable i.(i=5)

=> fun(i=fun(fun(i))); becomes fun(5); is called and it return 6 and nowhere the return value is stored.

Step 4: printf("%d\n", i); It prints the value of variable i.(5)

Hence the output is '5'.

Discussion:
17 comments Page 2 of 2.

Deependra said:   9 years ago
The value of local variable i, can be change in function parameter? How?

Niharika said:   9 years ago
It is post increment right so the answer will be 3.

Ranjeet said:   8 years ago
The right answer is 6.

Mohammed Hessen said:   8 years ago
Delete the variable i in this line;

fun(i=fun(fun(i)));
TO BE
fun(fun(fun(i)));
and it will return 3.

Shashi said:   8 years ago
#include<stdio.h>
int check (int, int);

int main()
{

int check(int i,int j)
{
return 34;
}
float n=1;
int c;
c = check(10, 20);
printf("c=%d\n", c);

return 0;
}
int check(int i, int j)
{
int *p, *q;
p=&i;
q=&j;
return i>=45 ? *p:*q;

}

Please, explain why it gives output as 34?

Rajesh said:   7 years ago
How to say we are not saving value of i?

Jetha lal said:   3 years ago
@Shashi.

First, the control will come on main and in the main check will call and directly it will return 34 and 34 will be get stored in c like c=34.

Now c will print so 34 will print and then the compiler go to the next line and find return 0 to the main (), return 0 to the main () is a message for a compiler that its work has been done.
So it will stop.

Hope you will get it.


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