C Variable Declaration and Scope

• Last Updated : 09 Aug, 2019

12

Question 1

Consider the following two C lines

int var1;

extern int var2;

Run on IDEWhich of the following statements is correct

A

Both statements only declare variables, don't define them.

B

First statement declares and defines var1, but second statement only declares var2

C

Both statements declare define variables var1 and var2

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Question 2

Predict the output

#include <stdio.h>

int var = 20;

int main()

{

    int var = var;

    printf("%d ", var);

    return 0;

}

Run on IDE

A

Garbage Value

B

20

C

Compiler Error

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Question 3

#include <stdio.h>

extern int var;

int main()

{

    var = 10;

    printf("%d ", var);

    return 0;

}

Run on IDE

A

Compiler Error: var is not defined

B

20

C

0

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Question 4

#include <stdio.h>

extern int var = 0;

int main()

{

    var = 10;

    printf("%d ", var);

    return 0;

}

Run on IDE

A

10

B

Compiler Error: var is not defined

C

0

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Question 5

Output?

int main()

{

  {

      int var = 10;

  }

  {

      printf("%d", var); 

  }

  return 0;

}

Run on IDE

A

10

B

Compiler Error

C

Garbage Value

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Question 6

Output?

#include <stdio.h>

int main()

{

  int x = 1, y = 2, z = 3;

  printf(" x = %d, y = %d, z = %d n", x, y, z);

  {

       int x = 10;

       float y = 20;

       printf(" x = %d, y = %f, z = %d n", x, y, z);

       {

             int z = 100;

             printf(" x = %d, y = %f, z = %d n", x, y, z);

       }

  }

  return 0;

}

Run on IDE

A

x = 1, y = 2, z = 3x = 10, y = 20.000000, z = 3x = 1, y = 2, z = 100

B

Compiler Error

C

x = 1, y = 2, z = 3x = 10, y = 20.000000, z = 3x = 10, y = 20.000000, z = 100 

D

x = 1, y = 2, z = 3x = 1, y = 2, z = 3x = 1, y = 2, z = 3

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Question 7

int main()

{

  int x = 032;

  printf("%d", x);

  return 0;

}

Run on IDE

A

32

B

0

C

26

D

50

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Question 8

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

int a;

int main()

{

   int b;

   // ..

   // ..

}

int c;

Run on IDE

A

a

B

b

C

c

D

All have same scope

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Question 9

Consider the following variable declarations and definitions in C

i) int var_9 = 1;

ii) int 9_var = 2;

iii) int _ = 3;

Run on IDEChoose the correct statement w.r.t. above variables.

A

Both i) and iii) are valid.

B

Only i) is valid.

C

Both i) and ii) are valid.

D

All are valid.

C Variable Declaration and Scope    C Quiz - 101    
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Question 10

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;

}

Run on IDE

A

It’ll always print Equal.

B

It’ll always print Not Equal.

C

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