C++ Data Types Quiz - MCQ Questions and Answers

Welcome to our blog post titled "C++ Data Types Quiz - MCQ Questions and Answers." This interactive quiz is designed for programmers and students who wish to solidify their understanding of data types in C++, a cornerstone concept in programming. 

Whether you are a beginner looking to get a firm grip on the basics or an experienced coder aiming to refresh your knowledge, these 20 multiple-choice questions cover a wide range of topics related to C++ data types. From simple built-in types to more complex derived types, each question is crafted to challenge and enhance your understanding, complete with comprehensive answers for self-assessment. Dive in and test your mastery of C++ data types!

1. What is the size of 'int' data type in C++?

a) Always 4 bytes

b) Always 2 bytes

c) Compiler dependent

d) 8 bytes

Answer:

c) Compiler dependent

Explanation:

The size of the 'int' data type in C++ is compiler dependent and can vary based on the architecture (32-bit or 64-bit systems). Typically, it is 4 bytes on most modern compilers.

2. What data type would you use to store a character in C++?

a) int

b) float

c) char

d) string

Answer:

c) char

Explanation:

The 'char' data type is used in C++ to store a single character.

3. Which data type is used to store boolean values in C++?

a) bool

b) int

c) bit

d) boolean

Answer:

a) bool

Explanation:

The 'bool' data type is used in C++ to store boolean values, which can be either true or false.

4. What is the purpose of the 'double' data type in C++?

a) To store large integer values

b) To store characters

c) To store floating-point numbers with double-precision

d) To store boolean values

Answer:

c) To store floating-point numbers with double-precision

Explanation:

The 'double' data type is used for floating-point numbers with double the precision of the 'float' type, allowing it to represent numbers with greater accuracy.

5. Which of the following is an example of an unsigned data type in C++?

a) int

b) float

c) unsigned int

d) double

Answer:

c) unsigned int

Explanation:

'unsigned int' is an example of an unsigned data type in C++, which means it can only represent non-negative numbers.

6. How do you declare a constant variable in C++?

a) const dataType variableName = value;

b) constant dataType variableName = value;

c) dataType constant variableName = value;

d) dataType variableName = const value;

Answer:

a) const dataType variableName = value;

Explanation:

A constant variable in C++ is declared using the 'const' keyword followed by the data type, variable name, and value. It represents a value that cannot be changed.

7. What is the default value of a static variable in C++?

a) 0

b) 1

c) Null

d) Undefined

Answer:

a) 0

Explanation:

In C++, a static variable is automatically initialized to zero if no other initialization is provided.

8. What is the correct way to define a long double variable in C++?

a) long double variableName;

b) double long variableName;

c) ldouble variableName;

d) dlong variableName;

Answer:

a) long double variableName;

Explanation:

The 'long double' keyword is used to declare a variable with extended precision for floating-point numbers.

9. What is the range of values that can be stored in a 'char' data type in C++?

a) -128 to 127

b) 0 to 255

c) -32768 to 32767

d) Depends on the compiler

Answer:

d) Depends on the compiler

Explanation:

The range of values for a 'char' can be either -128 to 127 or 0 to 255, depending on whether the char is signed or unsigned, which is compiler-dependent.

10. What data type should be used for a variable that needs to store very large integers in C++?

a) int

b) long

c) long long

d) double

Answer:

c) long long

Explanation:

The 'long long' data type in C++ is used for storing very large integer values, typically having a size of at least 64 bits.

11. Which of the following is a floating-point type in C++?

a) int

b) double

c) char

d) unsigned int

Answer:

b) double

Explanation:

'double' is a floating-point type in C++, used for storing decimal numbers.

12. What is the main difference between 'float' and 'double' in C++?

a) Different range of values

b) Different precision level

c) Different size in memory

d) Both b) and c)

Answer:

d) Both b) and c)

Explanation:

The main differences between 'float' and 'double' are their precision levels and sizes in memory. 'double' has higher precision and usually takes up more memory space than 'float'.

13. What does the 'auto' keyword do in C++?

a) Automatically initializes variables

b) Allows the compiler to automatically deduce the type of the variable

c) Creates a variable that changes type

d) Generates automatic constants

Answer:

b) Allows the compiler to automatically deduce the type of the variable

Explanation:

The 'auto' keyword allows the compiler to automatically deduce the type of a variable from its initializer.

14. Which of the following is the correct way to declare a pointer variable in C++?

a) int* ptr;

b) int ptr*;

c) *int ptr;

d) ptr int*;

Answer:

a) int* ptr;

Explanation:

A pointer variable in C++ is declared by placing an asterisk (*) before the variable name, after the data type.

15. What is the size of the 'void' data type in C++?

a) 1 byte

b) 2 bytes

c) 4 bytes

d) Void data type has no size

Answer:

d) Void data type has no size

Explanation:

The 'void' data type represents the absence of a type and therefore has no size.

16. What is the purpose of the 'enum' data type in C++?

a) To define a set of integer constants

b) To create anonymous objects

c) To declare new classes

d) To define floating-point constants

Answer:

a) To define a set of integer constants

Explanation:

The 'enum' (enumeration) data type is used to define a set of named integer constants, which improves the readability of the code.

17. What is the maximum value of an unsigned int in C++?

a) 2^16 - 1

b) 2^32 - 1

c) 65535

d) Depends on the compiler

Answer:

b) 2^32 - 1

Explanation:

The maximum value of an unsigned int is typically 2^32 - 1, but it can vary based on the compiler and architecture.

18. What is typecasting in C++?

a) Changing a variable from one type to another

b) Casting a variable to a new value

c) Removing the type from a variable

d) Declaring a new type

Answer:

a) Changing a variable from one type to another

Explanation:

Typecasting in C++ is the process of converting a variable from one data type to another. It can be implicit or explicit.

19. What is the range of values for a 'short int' in C++?

a) -32768 to 32767

b) -2147483648 to 2147483647

c) 0 to 65535

d) Depends on the compiler

Answer:

a) -32768 to 32767

Explanation:

The range of values for a 'short int' is typically -32768 to 32767, representing a 16-bit signed integer.

20. What is the default value of a static local variable in a function in C++?

a) 0

b) 1

c) Null

d) Undefined

Answer:

a) 0

Explanation:

Static local variables in functions in C++ are automatically initialized to zero if no other initialization is provided.