Consider the following C - code : C #include <stdio.h> int foo(int a) { printf("%d",a); return 0; } int main() { foo; return 0; }

No compile error but foo function wouldn’t be executed. The program wouldn 't print anything.

It’ll result in compile error because foo is used without parentheses.

No compile error and some garbage value would be passed to foo function. This would make foo to be executed with output “garbage integer”.

No compile error and ZERO (i.e. 0) would be passed to foo function. This would make foo to be executed with output 0.

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C Input and Output

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Question 1

Predict the output of the below program:

#include <stdio.h>

int main()
{
    printf("%c ", 5["GeeksQuiz"]);
    return 0;
}

Compile-time error
Runtime error
Q
s

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Question 2

Which of the following is the standard input stream in C?

stdout
Runtime error
stdin
stdfile

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Question 3

Which of the following is true

gets() can read a string with newline characters but a normal scanf() with %s can not.
gets() can read a string with spaces but a normal scanf() with %s can not.
gets() can always replace scanf() without any additional code.
None of the above

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Question 4

#include<stdio.h>

int main()
{
    char *s = "Geeks Quiz";
    int n = 7;
    printf("%.*s", n, s);
    return 0;
}

Geeks Quiz
Nothing is printed
Geeks Q
Geeks Qu

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Question 5

Predict the output of following program?

#include <stdio.h>
int main(void) 
{
   int x = printf("GeeksQuiz");
   printf("%d", x);
   return 0;
}

GeeksQuiz9
GeeksQuiz10
GeeksQuizGeeksQuiz
GeeksQuiz1

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Question 6

Output of following program?

#include<stdio.h>
int main()
{
    printf("%d", printf("%d", 1234));
    return 0;
}

12344
12341
11234
41234

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Question 7

What is the return type of getchar()?

int
char
unsigned char
float

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Question 8

Normally user programs are prevented from handling I/O directly by I/O instructions in them. For CPUs having explicit I/O instructions, such I/O protection is ensured by having the I/O instructions privileged. In a CPU with memory mapped I/O, there is no explicit I/O instruction. Which one of the following is true for a CPU with memory mapped I/O?

I/O protection is ensured by operating system routine (s)
I/O protection is ensured by a hardware trap
I/O protection is ensured during system configuration
I/O protection is not possible

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Question 9

Consider the following C - code :

#include <stdio.h>

int foo(int a)
{
 	printf("%d",a);
	return 0;
}

int main()
{
 	foo;
 	return 0;
}

It’ll result in compile error because foo is used without parentheses.
No compile error and some garbage value would be passed to foo function. This would make foo to be executed with output “garbage integer”.
No compile error but foo function wouldn’t be executed. The program wouldn\'t print anything.
No compile error and ZERO (i.e. 0) would be passed to foo function. This would make foo to be executed with output 0.

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Question 10

"Why is the & (address-of) operator used with scanf() when reading integer values?

To specify the format of the input.
To store the input at the variable’s memory address.
To perform pointer arithmetic.
It is optional and does not affect the function’s behavior.

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