C++ Programming MCQ – Constants Quizs Question

Q 1. The constants are also called as _____________
A. const
B. literals
C. preprocessor
D. variables

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Answer:-B. literals

Explanation

Other name for Constants are literals.

Q 2. What are the parts of the literal constants?
A. integer numerals
B. floating-point numerals
C. strings and boolean values
D. all of the mentioned

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Answer:-D. all of the mentioned

Explanation

Because these are the types used to declare variables and so these can be declared as constants.

Q 3. How are the constants declared?
A. const keyword
B. #define preprocessor
C. both const keyword and #define preprocessor
D. $define

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Answer:-C. both const keyword and #define preprocessor

Explanation

The const will declare with a specific type value and #define is used to declare user-defined constants.

Q 4. What will be the output of the following C++ code?

#include <iostream>

using namespace std;

int main()

{

int const p = 5;

cout << ++p;

return 0;

}

A. 5
B. 6
C. 8
D. Error

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Answer:-D. Error

Explanation

We cannot modify a constant integer value.

Q 5. What will be the output of the following C++ code?

#include <iostream>

using namespace std;

#define PI 3.14159

int main ()

{

float r = 2;

float circle;

circle = 2 * PI * r;

cout << circle;

return 0;

}

A. 12.5664
B. 13.5664
C. 10.9960
D. 15.4536

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Answer:-A. 12.5664

Explanation

In this program, we are finding the area of the circle by using concern formula. Output: $ g++ cons.cpp $ a.out 12.5664

Q 6. Which of the following statement is not true about Pre-processors Directives?
A. These are lines read and processed by the pre-processor
B. They end with a semicolon
C. These must be written on their own line
D. They do not produce any code by themselves

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Answer:-B. They end with a semicolon

Explanation

No terminating character required for preprocessor directives statements.

Q 7. Regarding the following statement which of the statements is true?

const int a = 100;

A. Declares a variable a with 100 as its initial value
B. Declares a construction a with 100 as its initial value
C. Declares a constant a whose value will be 100
D. Constructs an integer type variable with an as identifier and 100 as the value

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Answer:-C. Declares a constant a whose value will be 100

Explanation

Because the const is used to declare non-changeable values only.

Q 8. The difference between x and ‘x’ is?
A. The first one refers to a variable whose identifier is x and the second one refers to the character constant x
B. The first one is a character constant x and the second one is the string literal x
C. Both are same
D. Both are string literal

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Answer:-A. The first one refers to a variable whose identifier is x and the second one refers to the character constant x

Explanation

In a C++ code, names with quotes like ‘x’ represent a character or string(in case of a collection of characters) whereas without quotes they represent an identifier.

Q 9. How to declare a wide character in the string literal?
A. W prefix
B. l prefix
C. L prefix
D. Z prefix

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Answer:-C. L prefix

Explanation

It can turn this as the wide character instead of narrow characters.