C Variable Declaration and Scope

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Question 1

Predict the output

#include <stdio.h>
int var = 20;
int main()
{
    int var = var;
    printf("%d ", var);
    return 0;
}

Garbage Value
20
Compiler Error

Question 2

Consider the program below in a hypothetical language which allows global variable and a choice of call by reference or call by value methods of parameter passing.

 int i ;
program main ()
{
    int j = 60;
    i = 50;
    call f (i, j);
    print i, j;
}
procedure f (x, y)
{           
    i = 100;
    x = 10;
    y = y + i ;
}

Which one of the following options represents the correct output of the program for the two parameter passing mechanisms?

Call by value : i = 70, j = 10; Call by reference : i = 60, j = 70
Call by value : i = 50, j = 60; Call by reference : i = 50, j = 70
Call by value : i = 10, j = 70; Call by reference : i = 100, j = 60
Call by value : i = 100, j = 60; Call by reference : i = 10, j = 70

Question 3

Consider the following statements S1, S2 and S3 : S1 : In call-by-value, anything that is passed into a function call is unchanged in the caller’s scope when the function returns. S2 : In call-by-reference, a function receives implicit reference to a variable used as argument. S3 : In call-by-reference, caller is unable to see the modified variable used as argument.

S3 and S2 are true.
S3 and S1 are true.
S2 and S1 are true.
S1, S2, S3 are true.

Question 4

When an array is passed as parameter to a function, which of the following statements is correct?

The function can change values in the original array.
In C, parameters are passed by value, the function cannot change the original value in the array.
It results in compilation error when the function tries to access the elements in the array.
Results in a run time error when the function tries to access the elements in the array.

Question 5

Assume that the program ‘P’ is implementing parameter passing with ‘call by reference’. What will be printed by following print statements in P? Program P( ) { x = 10; y = 3; funb (y, x, x) print x; print y; } funb (x, y, z) { y = y + 4; z = x + y + z; }

10, 7
31, 3
10, 3
31, 7

Question 6

Given i= 0, j = 1, k = – 1 x = 0.5, y = 0.0 What is the output of given ‘C’ expression ? x * 3 & & 3 || j | k

-1
0
1
2

Question 7

Find out the correct statement for the following program.

#include "stdio.h"

int * gPtr;

int main()
{
 int * lPtr = NULL;

 if(gPtr == lPtr)
 {
   printf("Equal!");
 }
 else
 {
  printf("Not Equal");
 }

 return 0;
}

It’ll always print Equal.
It’ll always print Not Equal.
Since gPtr isn’t initialized in the program, it’ll print sometimes Equal and at other times Not Equal.

Question 8

Consider the following variable declarations and definitions in C

i) int var_9 = 1;
ii) int 9_var = 2;
iii) int _ = 3;

Choose the correct statement w.r.t. above variables.

Both i) and iii) are valid.
Only i) is valid.
Both i) and ii) are valid.
All are valid.

Question 9

Consider the following C program, which variable has the longest scope?

int a;
int main()
{
   int b;
   // ..
   // ..
}
int c;

a
b
c
All have same scope

Question 10

int main()
{
  int x = 032;
  printf("%d", x);
  return 0;
}

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