Explore topic-wise MCQs in C Programming.

This section includes 24 Mcqs, each offering curated multiple-choice questions to sharpen your C Programming knowledge and support exam preparation. Choose a topic below to get started.

1.

Which of the following is the correct output for the program given below?

#include<studio.h>
int main()
{
 union a
 { 
 short int i;
 char ch[1];
 };
 union a u;
 u.ch[0] = 10;
 u.ch[1] = 20;
 printf("%d %d %d n", u.ch[0], u.ch[1], u.i);
 return 0;
}

A. 10 20 5130
B. 5130 10 20
C. 10 20 50
D. None of the above
Answer» B. 5130 10 20
Discussion
2.

In the following C code, we can access the 1st character of the string sval by using _______.
#include <stdio.h>
 struct
 {
 char *Name;
 union
 {
 char *Str;
 } u;
 } tab[15];
A. tab[i].u.Str[0].
B. *symtab[i].u.Str
C. Both tab[i].u.Str[0]. & *tab[i].u.Str
D. You cannot have union inside structure
E. None of these
Answer» D. You cannot have union inside structure
Discussion
3.

What type of data is holded by variable u int in the following C code?
#include <stdio.h>
 union Example
 {
 int Nval;
 float Fval;
 char *Sval;
 } e;
A. Will be large enough to hold the smallest of the three types;
B. Will be large enough to hold the all of the three types;
C. Will be large enough to hold the largest of the three types;
D. All of above
E. None of these
Answer» D. All of above
Discussion
4.

What would be the size of the following union declaration? (Assuming size of double = 8, size of int = 4, size of char = 1)
#include <stdio.h>
 union Test
 {
 double n1;
 int n2[10];
 char n;
 }t;
A. 80
B. 8
C. 4
D. 40
E. None of these
Answer» E. None of these
Discussion
5.

Which member of the union will be active after REF LINE in the following C code?
#include <stdio.h>
 union test
 {
 int n;
 float fl;
 char ch;
 };
 union test t = {11,12.25, N }; //REF LINE
A. n
B. fl
C. ch
D. Such declaration are illegal
E. None of these
Answer» B. fl
Discussion
6.

What will be the output of the following C code?
#include <stdio.h>
 union U
 {
 int m;
 char s;
 };
 int main()
 {
 union U u, uu;
 u.m = 65;
 uu.s = 32;
 printf("%d n", u.s);
 }
A. Compilation Error
B. Garbage value
C. 65
D. 32
E. None of these
Answer» D. 32
Discussion
7.

What will be the output of the following C code?
#include <stdio.h>
 union
 {
 int n;
 char ch;
 }U;
 int main()
 {
 U.ch = 201;
 printf("%d n", sizeof(U));
 }
A. sizeof(int) + sizeof(char)
B. sizeof(char)
C. Compilation Error
D. Depends on the compiler
E. None of these
Answer» C. Compilation Error
Discussion
8.

What will be the output of the following C code?
#include <stdio.h>
 union
 {
 int n;
 char ch;
 }U;
 int main()
 {
 U.n = 10;
 printf("%d n", sizeof(U));
 }
A. sizeof(int)
B. Depends on the compiler
C. sizeof(int) + sizeof(char)
D. Compilation Error
E. None of these
Answer» B. Depends on the compiler
Discussion
9.

What will be the output of the following C code (Assuming size of int and float is 4)?
#include <stdio.h>
 union
 {
 int Nval;
 float Fval;
 } U;
 void main()
 {
 printf("%d", sizeof(U));
 }
A. 32
B. 16
C. 8
D. 4
E. None of these
Answer» E. None of these
Discussion
10.

What will be the output of the following C code?
#include <stdio.h>
 union Employee
 {
 int N;
 float F;
 };
 void main()
 {
 union Employee emp;
 emp.N = 26;
 printf("%d", emp.N);
 }
A. Garbage value
B. Compilation Error
C. 26
D. Undefined behaviour
E. None of these
Answer» D. Undefined behaviour
Discussion
11.

What will be the output of the following C code? (Assuming size of char = 1, int = 4, double = 8)
#include <stdio.h>
 union Example
 {
 int n1;
 double n2;
 char ch;
 }E;
 int main()
 {
 E.ch = 'B';
 E.n1 = 100;
 printf("%d", sizeof(E));
 }
A. 32
B. 16
C. 8
D. 4
E. 2
Answer» D. 4
Discussion
12.

Which of the following share a similarity in syntax?
1. Union
2. Structure
3. Arrays 
4. Pointers
A. 1 and 2
B. 3 and 4
C. 1, 3 and 4
D. 1 and 3
E. None of these
Answer» B. 3 and 4
Discussion
13.

What will be the output of the following C code?
#include <stdio.h>
 union U
 {
 int N;
 float F;
 };
 int main()
 {
 union U u, uu;
 u.N = 200;
 printf("%f n", u.F);
 }
A. Implementation dependent
B. Compilation Error
C. 200.000000
D. 0.000000
E. None of these
Answer» E. None of these
Discussion
14.

What will be the output of the following C code?
#include <stdio.h>
 union U
 {
 int m;
 char Str;
 }s = {.Str = 99};
 int main()
 {
 printf("%d n", s.Str);
 }
A. Compilation Error
B. Depends on compiler
C. Garbage value
D. 99
E. None of these
Answer» E. None of these
Discussion
15.

What will be the output of the following C code?
#include <stdio.h>
 union S
 {
 int n;
 char ch;
 }u = {100, 99};
 int main()
 {
 printf("%d n", u.ch);
 }
A. 99
B. 100
C. Compilation Error
D. Garbage value
E. None of these
Answer» C. Compilation Error
Discussion
16.

The size of a union is determined by the size of the __________.

A. Biggest member in the union
B. Sum of the sizes of all members
C. First member in the union
D. Last member in the union
E. None of these
Answer» B. Sum of the sizes of all members
Discussion
17.

In the following C code, we can access the 1st character of the string sval by using _______.

A. tab[i].u.Str[0].
B. *symtab[i].u.Str
C. Both tab[i].u.Str[0]. & *tab[i].u.Str
D. You cannot have union inside structure
E. None of these
Answer» D. You cannot have union inside structure
Discussion
18.

What will be the output of the following C code (Assuming size of int and float is 4)?

A. 32
B. 16
C. 8
D. 4
E. None of these
Answer» E. None of these
Discussion
19.

What would be the size of the following union declaration? (Assuming size of double = 8, size of int = 4, size of char = 1)

A. 80
B. 8
C. 4
D. 40
E. None of these
Answer» E. None of these
Discussion
20.

Which member of the union will be active after REF LINE in the following C code?

A. n
B. fl
C. ch
D. Such declaration are illegal
E. None of these
Answer» B. fl
Discussion
21.

What will be the output of the following C code? (Assuming size of char = 1, int = 4, double = 8)

A. 32
B. 16
C. 8
D. 4
E. 2
Answer» D. 4
Discussion
22.

Members of a union are accessed as________________.

A. union-pointer->member
B. union-name.member
C. both union-pointer->member & union-name.member
D. union-name.pointer
E. None of these
Answer» D. union-name.pointer
Discussion
23.

What type of data is holded by variable u int in the following C code?

A. Will be large enough to hold the smallest of the three types;
B. Will be large enough to hold the all of the three types;
C. Will be large enough to hold the largest of the three types;
D. All of above
E. None of these
Answer» D. All of above
Discussion
24.

Which of the following share a similarity in syntax?

A. 1 and 2
B. 3 and 4
C. 1, 3 and 4
D. 1 and 3
E. None of these
Answer» B. 3 and 4
Discussion