C Programming - Strings - Discussion
Discussion Forum : Strings - Find Output of Program (Q.No. 6)
6.
What will be the output of the program If characters 'a', 'b' and 'c' enter are supplied as input?
#include<stdio.h>
int main()
{
void fun();
fun();
printf("\n");
return 0;
}
void fun()
{
char c;
if((c = getchar())!= '\n')
fun();
printf("%c", c);
}
Answer: Option
Explanation:
Step 1: void fun(); This is the prototype for the function fun().
Step 2: fun(); The function fun() is called here.
The function fun() gets a character input and the input is terminated by an enter key(New line character). It prints the given character in the reverse order.
The given input characters are "abc"
Output: cba
Discussion:
31 comments Page 2 of 4.
Priyanka said:
1 decade ago
Its an recursion.
In recursion stack fill as like staircase.
So as by it executing stack become empty.
As stack empty it is in FILO means which is first in is get last out.
So it prints reverse.
In recursion stack fill as like staircase.
So as by it executing stack become empty.
As stack empty it is in FILO means which is first in is get last out.
So it prints reverse.
Sony Sharma said:
1 decade ago
I am not understanding this prblm.
@Navdeep Jain can you please explain it more? Why we are only giving a, b and c as input. We can give other alphabets also.
And which part of code is working as stack?
@Navdeep Jain can you please explain it more? Why we are only giving a, b and c as input. We can give other alphabets also.
And which part of code is working as stack?
Bhargav said:
1 decade ago
Why void fun() is declared inside the main ?
Durai said:
1 decade ago
How come 'char c' prints three characters continuously as array?
Vasuveer singh said:
1 decade ago
Hello friend,
At the very beginning the input is "a" so condition holds true hence it creates the first recursive call.
Now the input is "b" so condition holds true hence it creates the second recursive call.
Now the input is "c" so condition holds true hence it creates the third recursive call.
Now the input is "enter" so condition holds false hence it do not creates the recursive call but goes to print command, which prints "c".
Now control goes back to 2nd call of fun() in which c = 'b'.
Now control goes back to 1st call of fun() in which c = 'a'.
At the very beginning the input is "a" so condition holds true hence it creates the first recursive call.
Now the input is "b" so condition holds true hence it creates the second recursive call.
Now the input is "c" so condition holds true hence it creates the third recursive call.
Now the input is "enter" so condition holds false hence it do not creates the recursive call but goes to print command, which prints "c".
Now control goes back to 2nd call of fun() in which c = 'b'.
Now control goes back to 1st call of fun() in which c = 'a'.
Anshul Jain said:
10 years ago
I run this program in turbo c++.
My answer is (null).
Any one explain me?
My answer is (null).
Any one explain me?
Pravas said:
10 years ago
Answer is cba because, in the loop if((c=getchar()!="\n").
That means output character should not c ="\n" that is a (c!=a), so, first c is printed then b then a.
That means output character should not c ="\n" that is a (c!=a), so, first c is printed then b then a.
Deepak Chauhan said:
10 years ago
@Vasuveer singh what you wrote is theoretically correct but here after asking for a character again it is asking for character.
Hence after 'a' is typed and enter key is pressed it will take enter ='\0' as input for next character and will exit the loop.
Hence after 'a' is typed and enter key is pressed it will take enter ='\0' as input for next character and will exit the loop.
Manisha said:
9 years ago
In order to understand it clearly, we can break this program as below (considering input as abc)
void fun()
{
char c;
if((c = getchar())!= '\n')
{
char c;
if ((c = getchar())!= '\n')
{
char c;
if ((c = getchar())!= '\n')
{
..
}
else
{
printf("%c", c);
}
}
else
{
printf("%c", c);
}
}
else
{
printf("%c", c);
}
}
void fun()
{
char c;
if((c = getchar())!= '\n')
{
char c;
if ((c = getchar())!= '\n')
{
char c;
if ((c = getchar())!= '\n')
{
..
}
else
{
printf("%c", c);
}
}
else
{
printf("%c", c);
}
}
else
{
printf("%c", c);
}
}
Amandeep said:
9 years ago
I'm not getting this. Once we press enter the if statement is not satisfied hence it should execute the printf statement and print the last char entered and that's it. There is no further call to the function. How can it print it in reverse order? please somebody explain me.
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