C Programming - Functions - Discussion
Discussion Forum : Functions - Find Output of Program (Q.No. 5)
5.
What will be the output of the program?
#include<stdio.h>
void fun(int);
typedef int (*pf) (int, int);
int proc(pf, int, int);
int main()
{
int a=3;
fun(a);
return 0;
}
void fun(int n)
{
if(n > 0)
{
fun(--n);
printf("%d,", n);
fun(--n);
}
}
Discussion:
96 comments Page 3 of 10.
Tushar said:
8 years ago
How does calling function works ?
BhavadipGothadiyaBG said:
8 years ago
How it's Possible?
Kowsik said:
8 years ago
When fun(0) is called 0>0 condition fail and it will not enter in the loop further. So the program will not provide any output. Correct me if I am wrong.
Asha said:
8 years ago
Thank you guys. I understood stack.
Insiya said:
8 years ago
The main thing to b noted here is that once the if the condition fails only the inner function is returned the remaining calling functions r still there.
The value of n is 3 initially
Fun(3)
{
3 > 0 true
{ fun(2) is called
Printf(2)
Fun(1)}
}
Now wat is fun(2) value . we need to find it
So fun(2)
{
2>0 true
{ fun(1)
Print(1)
Fun(0) }
Find fun(1)
{ 1>0 true
Fun(0)
Print(0)
Fun (-1)
}
Find fun(0)
{
0>0 false so function returns
}
Substitution starts from the most inner loop so it will start from fun(0).
So by back substitution 0 is printed then function returns to fun(1) call and prints 1 the goes to fun (0) which returns again as fun(0) fails conditions so the function returns to fun(2) call and prints 2 and the fun(1) and wch brings us to fun(0) and prints 0.
The value of n is 3 initially
Fun(3)
{
3 > 0 true
{ fun(2) is called
Printf(2)
Fun(1)}
}
Now wat is fun(2) value . we need to find it
So fun(2)
{
2>0 true
{ fun(1)
Print(1)
Fun(0) }
Find fun(1)
{ 1>0 true
Fun(0)
Print(0)
Fun (-1)
}
Find fun(0)
{
0>0 false so function returns
}
Substitution starts from the most inner loop so it will start from fun(0).
So by back substitution 0 is printed then function returns to fun(1) call and prints 1 the goes to fun (0) which returns again as fun(0) fails conditions so the function returns to fun(2) call and prints 2 and the fun(1) and wch brings us to fun(0) and prints 0.
Khan said:
8 years ago
When 0>0 the if statement fails then how the statements inside it will execute?
Manjunath Rk said:
8 years ago
Good explaination, Thanks @Sree.
Vidya said:
8 years ago
Well said @Sree. Thanks.
Fenil said:
8 years ago
Can anyone explain in brief?
As each time function is called & control is passed to function how printf statement will be executed?
As each time function is called & control is passed to function how printf statement will be executed?
Manu said:
8 years ago
I got it as 0,1,0,2,0,1,0.
How? Please tell me.
How? Please tell me.
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