Explore topic-wise MCQs in C Programming.

This section includes 50 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.

Point out the error in the program? #include int main() { union a { int i; char ch[2]; }; union a z1 = {512}; union a z2 = {0, 2}; return 0; }

A. Error: invalid union declaration
B. Error: in Initializing z2
C. No error
D. None of above
Answer» C. No error
Discussion
2.

Point out the error in the program? #include int main() { struct emp { char n[20]; int age; }; struct emp e1 = {"Dravid", 23}; struct emp e2 = e1; if(e1 == e2) printf("The structure are equal"); return 0; }

A. Prints: The structure are equal
B. Error: Structure cannot be compared using '=='
C. No output
D. None of above
Answer» C. No output
Discussion
3.

Point out the error in the program? #include int main() { struct bits { float f:2; }bit; printf("%d\n", sizeof(bit)); return 0; }

A. 4
B. 2
C. Error: cannot set bit field for float
D. Error: Invalid member access in structure
Answer» D. Error: Invalid member access in structure
Discussion
4.

Is it necessary that the size of all elements in a union should be same?

A. Yes
B. No
Answer» C.
Discussion
5.

What will be the output of the program in Turbo C (under DOS)? #include int main() { struct emp { char *n; int age; }; struct emp e1 = {"Dravid", 23}; struct emp e2 = e1; strupr(e2.n); printf("%s\n", e1.n); return 0; }

A. Error: Invalid structure assignment
B. DRAVID
C. Dravid
D. No output
Answer» C. Dravid
Discussion
6.

The '.' operator can be used access structure elements using a structure variable.

A. 1
B.
Answer» B.
Discussion
7.

Will the following declaration work? typedef struct s { int a; float b; }s;

A. Yes
B. No
Answer» B. No
Discussion
8.

If a char is 1 byte wide, an integer is 2 bytes wide and a long integer is 4 bytes wide then will the following structure always occupy 7 bytes? struct ex { char ch; int i; long int a; };

A. Yes
B. No
Answer» C.
Discussion
9.

What will be the output of the program given below in 16-bit platform ? #include int main() { enum value{VAL1=0, VAL2, VAL3, VAL4, VAL5} var; printf("%d\n", sizeof(var)); return 0; }

A. 1
B. 2
C. 4
D. 10
Answer» C. 4
Discussion
10.

A structure can contain similar or dissimilar elements

A. 1
B.
Answer» B.
Discussion
11.

Can we have an array of bit fields?

A. Yes
B. No
Answer» C.
Discussion
12.

What will be the output of the program in 16-bit platform (under DOS)? #include int main() { struct node { int data; struct node *link; }; struct node *p, *q; p = (struct node *) malloc(sizeof(struct node)); q = (struct node *) malloc(sizeof(struct node)); printf("%d, %d\n", sizeof(p), sizeof(q)); return 0; }

A. 2, 2
B. 8, 8
C. 5, 5
D. 4, 4
Answer» B. 8, 8
Discussion
13.

What will be the output of the program ? #include int main() { struct byte { int one:1; }; struct byte var = {1}; printf("%d\n", var.one); return 0; }

A. 1
B. -1
C. 0
D. Error
Answer» C. 0
Discussion
14.

Union elements can be of different sizes.

A. 1
B.
Answer» B.
Discussion
15.

What will be the output of the program ? #include struct course { int courseno; char coursename[25]; }; int main() { struct course c[] = { {102, "Java"}, {103, "PHP"}, {104, "DotNet"} }; printf("%d ", c[1].courseno); printf("%s\n", (*(c+2)).coursename); return 0; }

A. 103 DotNet
B. 102 Java
C. 103 PHP
D. 104 DotNet
Answer» B. 102 Java
Discussion
16.

What will be the output of the program ? #include int main() { int i=4, j=8; printf("%d, %d, %d\n", i|j&j|i, i|j&j|i, i^j); return 0; }

A. 12, 12, 12
B. 112, 1, 12
C. 32, 1, 12
D. -64, 1, 12
Answer» B. 112, 1, 12
Discussion
17.

By default structure variable will be of auto storage class

A. Yes
B. No
Answer» B. No
Discussion
18.

The '->' operator can be used to access structures elements using a pointer to a structure variable only

A. 1
B.
Answer» B.
Discussion
19.

Point out the error in the program in 16-bit platform? #include int main() { struct bits { int i:40; }bit; printf("%d\n", sizeof(bit)); return 0; }

A. 4
B. 2
C. Error: Bit field too large
D. Error: Invalid member access in structure
Answer» D. Error: Invalid member access in structure
Discussion
20.

The elements of union are always accessed using & operator

A. Yes
B. No
Answer» C.
Discussion
21.

A structure can be nested inside another structure.

A. 1
B.
Answer» B.
Discussion
22.

What will be the output of the program ? #include int main() { enum status {pass, fail, absent}; enum status stud1, stud2, stud3; stud1 = pass; stud2 = absent; stud3 = fail; printf("%d %d %d\n", stud1, stud2, stud3); return 0; }

A. 0, 1, 2
B. 1, 2, 3
C. 0, 2, 1
D. 1, 3, 2
Answer» D. 1, 3, 2
Discussion
23.

Point out the error in the program? typedef struct data mystruct; struct data { int x; mystruct *b; };

A. Error: in structure declaration
B. Linker Error
C. No Error
D. None of above
Answer» D. None of above
Discussion
24.

A pointer union CANNOT be created

A. Yes
B. No
Answer» C.
Discussion
25.

Which of the following statements correct about the below program? #include int main() { union a { int i; char ch[2]; }; union a u1 = {512}; union a u2 = {0, 2}; return 0; } 1: u2 CANNOT be initialized as shown. 2: u1 can be initialized as shown. 3: To initialize char ch[] of u2 '.' operator should be used. 4: The code causes an error 'Declaration syntax error'

A. 1, 2
B. 2, 3
C. 1, 2, 3
D. 1, 3, 4
Answer» D. 1, 3, 4
Discussion
26.

What will be the output of the program ? #include int main() { union var { int a, b; }; union var v; v.a=10; v.b=20; printf("%d\n", v.a); return 0; }

A. 10
B. 20
C. 30
D. 0
Answer» C. 30
Discussion
27.

Point out the error in the program? #include int main() { struct emp { char name[25]; int age; float bs; }; struct emp e; e.name = "Suresh"; e.age = 25; printf("%s %d\n", e.name, e.age); return 0; }

A. Error: Lvalue required/incompatible types in assignment
B. Error: invalid constant expression
C. Error: Rvalue required
D. No error, Output: Suresh 25
Answer» B. Error: invalid constant expression
Discussion
28.

Which of the following statements correctly assigns 12 to month using pointer variable pdt? #include struct date { int day; int month; int year; }; int main() { struct date d; struct date *pdt; pdt = &d; return 0; }

A. pdt.month = 12
B. &pdt.month = 12
C. d.month = 12
D. pdt->month = 12
Answer» E.
Discussion
29.

Point out the error in the program? #include int main() { struct a { float category:5; char scheme:4; }; printf("size=%d", sizeof(struct a)); return 0; }

A. Error: invalid structure member in printf
B. Error in this float category:5; statement
C. No error
D. None of above
Answer» C. No error
Discussion
30.

size of union is size of the longest element in the union

A. Yes
B. No
Answer» B. No
Discussion
31.

It is not possible to create an array of pointer to structures.

A. 1
B.
Answer» C.
Discussion
32.

one of elements of a structure can be a pointer to the same structure.

A. 1
B.
Answer» B.
Discussion
33.

Point out the error in the program? struct emp { int ecode; struct emp e; };

A. Error: in structure declaration
B. Linker Error
C. No Error
D. None of above
Answer» B. Linker Error
Discussion
34.

Can a structure can point to itself?

A. Yes
B. No
C. Yes
D. No
Answer» B. No
Discussion
35.

Nested unions are allowed

A. 1
B.
Answer» B.
Discussion
36.

Point out the error in the program? #include #include void modify(struct emp*); struct emp { char name[20]; int age; }; int main() { struct emp e = {"Sanjay", 35}; modify(&e); printf("%s %d", e.name, e.age); return 0; } void modify(struct emp *p) { p ->age=p->age+2; }

A. Error: in structure
B. Error: in prototype declaration unknown struct emp
C. No error
D. None of above
Answer» C. No error
Discussion
37.

Point out the error in the program? #include int main() { struct emp { char name[20]; float sal; }; struct emp e[10]; int i; for(i=0; i<=9; i++) scanf("%s %f", e[i].name, &e[i].sal); return 0; }

A. Error: invalid structure member
B. Error: Floating point formats not linked
C. No error
D. None of above
Answer» C. No error
Discussion
38.

What will be the output of the program ? #include int main() { struct value { int bit1:1; int bit3:4; int bit4:4; }bit={1, 2, 13}; printf("%d, %d, %d\n", bit.bit1, bit.bit3, bit.bit4); return 0; }

A. 1, 2, 13
B. 1, 4, 4
C. -1, 2, -3
D. -1, -2, -13
Answer» D. -1, -2, -13
Discussion
39.

What will be the output of the program ? #include int main() { enum days {MON=-1, TUE, WED=6, THU, FRI, SAT}; printf("%d, %d, %d, %d, %d, %d\n", MON, TUE, WED, THU, FRI, SAT); return 0; }

A. -1, 0, 1, 2, 3, 4
B. -1, 2, 6, 3, 4, 5
C. -1, 0, 6, 2, 3, 4
D. -1, 0, 6, 7, 8, 9
Answer» E.
Discussion
40.

What will be the output of the program ? #include int main() { enum days {MON=-1, TUE, WED=6, THU, FRI, SAT}; printf("%d, %d, %d, %d, %d, %d\n", ++MON, TUE, WED, THU, FRI, SAT); return 0; }

A. -1, 0, 1, 2, 3, 4
B. Error
C. 0, 1, 6, 3, 4, 5
D. 0, 0, 6, 7, 8, 9
Answer» C. 0, 1, 6, 3, 4, 5
Discussion
41.

Is there easy way to print enumeration values symbolically?

A. Yes
B. No
C. Yes
D. No
Answer» C. Yes
Discussion
42.

Will the following code work? #include #include struct emp { int len; char name[1]; }; int main() { char newname[] = "Rahul"; struct emp *p = (struct emp *) malloc(sizeof(struct emp) -1 + strlen(newname)+1); p->len = strlen(newname); strcpy(p -> name, newname); printf("%d %s\n", p->len, p->name); return 0; }

A. Yes
B. No
Answer» B. No
Discussion
43.

Which of the following statements correct about the below code? maruti.engine.bolts=25;

A. Structure bolts is nested within structure engine.
B. Structure engine is nested within structure maruti.
C. Structure maruti is nested within structure engine.
D. Structure maruti is nested within structure bolts.
Answer» C. Structure maruti is nested within structure engine.
Discussion
44.

Bit fields CANNOT be used in union.

A. 1
B.
Answer» C.
Discussion
45.

What will be the output of the program in 16 bit platform (Turbo C under DOS) ? #include int main() { struct value { int bit1:1; int bit3:4; int bit4:4; }bit; printf("%d\n", sizeof(bit)); return 0; }

A. 1
B. 2
C. 4
D. 9
Answer» C. 4
Discussion
46.

A union cannot be nested in a structure

A. 1
B.
C. 1
D.
Answer» C. 1
Discussion
47.

If the following structure is written to a file using fwrite(), can fread() read it back successfully? struct emp { char *n; int age; }; struct emp e={"IndiaBIX", 15}; FILE *fp; fwrite(&e, sizeof(e), 1, fp);

A. Yes
B. No
C. Yes
D. No
Answer» C. Yes
Discussion
48.

What will be the output of the program ? #include int main() { union a { int i; char ch[2]; }; union a u; u.ch[0]=3; u.ch[1]=2; printf("%d, %d, %d\n", u.ch[0], u.ch[1], u.i); return 0; }

A. 3, 2, 515
B. 515, 2, 3
C. 3, 2, 5
D. 515, 515, 4
Answer» B. 515, 2, 3
Discussion
49.

Which of the following statements correct about the below program? #include int main() { struct emp { char name[25]; int age; float sal; }; struct emp e[2]; int i=0; for(i=0; i<2; i++) scanf("%s %d %f", e[i].name, &e[i].age, &e[i].sal); for(i=0; i<2; i++) scanf("%s %d %f", e[i].name, e[i].age, e[i].sal); return 0; }

A. Error: scanf() function cannot be used for structures elements.
B. The code runs successfully.
C. Error: Floating point formats not linked Abnormal program termination.
D. Error: structure variable must be initialized.
Answer» D. Error: structure variable must be initialized.
Discussion
50.

Point out the error in the program? struct emp { int ecode; struct emp *e; };

A. Error: in structure declaration
B. Linker Error
C. No Error
D. None of above
Answer» D. None of above
Discussion