Which of the following will correctly print the number of arguments passed to a variadic macro in C99?

The correct answer is A: #define COUNT_ARGS(...) sizeof((int[]){__VA_ARGS__})/sizeof(int). C99 variadic macros don't have a built-in way to count arguments. Option A uses a clever technique with array size calculation. Option B references non-standard VA_NARGS. Options C and D use invalid syntax with token pasting.

Which of the following file modes in fopen() allows reading only?

The correct answer is B: "r". The 'r' mode opens a file for reading only. The file must exist, otherwise fopen() returns NULL.

Which string function modifies the original string in-place?

The correct answer is D: Both A and C. Both strtok() (modifies by replacing delimiters with '\0') and strcpy() (copies and overwrites destination) modify strings in-place.

What is the output of the following code? int x = 10; int *p = &x; printf("%d", *p);

The correct answer is A: 10. p is a pointer to x. *p dereferences the pointer, giving the value of x, which is 10.

What is the primary advantage of using structures in C?

The correct answer is B: To group related data of different types together. Structures allow you to combine multiple data types into a single composite type, making code organization and data management more efficient.

Home

Home › Subjects › C Programming › Pointers

C Programming
Pointers

C language from basics to advanced placement prep

27 Q 10 Topics Take Mock Test

Difficulty: All Easy Medium Hard 21–27 of 27

Topics in C Programming

All Basics & Syntax 86 Data Types & Variables 97 Control Flow 100 Functions 99 Arrays & Strings 100 Pointers 99 Structures & Unions 100 File Handling 100 Dynamic Memory 98 Preprocessor 99

Q.21 Easy Pointers

What is the size of a pointer variable on a 32-bit system?

A 2 bytes

B 4 bytes

C 8 bytes

D Depends on the data type

Correct Answer: B. 4 bytes

EXPLANATION

On a 32-bit system, all pointers are 4 bytes (32 bits) regardless of the data type they point to.

Test

Q.22 Easy Pointers

A pointer variable stores the _____ of another variable.

A value

B memory address

C data type

D size

Correct Answer: B. memory address

EXPLANATION

Pointers store memory addresses of variables. The address-of operator (&) retrieves this address.

Test

Q.23 Easy Pointers

Identify the output:
char *str = "Hello";
printf("%c", *str);

A H

B Hello

C e

D Address

Correct Answer: A. H

EXPLANATION

*str dereferences the pointer to get the first character of the string, which is 'H'.

Test

Q.24 Easy Pointers

Which of the following is NOT a valid pointer declaration?

A int *p;

B float *q;

C void *r;

D int &s;

Correct Answer: D. int &s;

EXPLANATION

& is a reference operator used in C++, not in C. In C, pointers are declared using *.

Test

Q.25 Easy Pointers

What is a NULL pointer?

A Pointer pointing to address 0

B Uninitialized pointer

C Pointer with no name

D Invalid pointer

Correct Answer: A. Pointer pointing to address 0

EXPLANATION

A NULL pointer is a pointer that points to memory address 0, indicating it doesn't point to any valid memory location.

Test

Q.26 Easy Pointers

What will be the size of a pointer variable on a 64-bit system?

A 2 bytes

B 4 bytes

C 8 bytes

D 16 bytes

Correct Answer: C. 8 bytes

EXPLANATION

On a 64-bit system, a pointer is 8 bytes (64 bits) regardless of the data type it points to.

Test

Q.27 Easy Pointers

Which operator is used to get the address of a variable in C?

A *

B &

C ->

D .

Correct Answer: B. &

EXPLANATION

The & operator (address-of operator) returns the memory address of a variable.

Test

1 2 3

All Subjects & Topics

Govt. Exams

Entrance Exams

Teacher Exams

Subjects

Quick Links

C Programming Pointers

C Programming
Pointers