C++ interview questions and answers focuses on “Macros”. One shall practice these interview questions to improve their C++ programming skills needed for various interviews entrance exams and other competitive exams. These questions can be attempted by anyone focusing on learning C++ programming language. They can be a beginner, fresher, engineering graduate or an experienced IT professional. Our C++ interview questions come with the detailed explanation of the answers which helps in better understanding of C++ concepts.
C++ interview questions on “Macros” along with answers, explanations and/or solutions:
Q 1. which keyword is used to define the macros in c++?
A. macro
B. define
C. #macro
D. #define
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Answer:-D. #defineExplanation
#define is the keyword which is used to define the macros in c++.Q 2. Which symbol is used to declare the pre-processor directives?
A. #
B. $
C. *
D. ^
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Answer:-A. #Explanation
# symbol is used to declare the pre-processor directives.Q 3. How many types of macros are there in c++?
A. 1
B. 2
C. 3
D. 4
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Answer:-B. 2Explanation
There are two types of macros. They are object-like and function-like.Q 4. What is the mandatory pre-processor directive for c++?
A. #include <iostream>
B. #define <iostream>
C. #undef <iostream>
D. #macro <iostream>
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Answer:-A. #includeExplanation
For a c++ program to execute, we need #includeQ 5. What will be the output of the following C++ code?
#include <iostream>
using namespace std;
#define MIN(a,b) (((a)<(b)) ? a : b)
int main ()
{
float i, j;
i = 100.1;
j = 100.01;
cout <<“The minimum is ” << MIN(i, j) << endl;
return 0;
}
A. 100.01
B. 100.1
C. compile time error
D. 100
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Answer:-A. 100.01Explanation
In this program, we are getting the minimum number using conditional operator. Output: $ g++ mac3.cpp $ a.out The minimum value is 100.01Q 6. What will be the output of the following C++ code?
#include <iostream>
using namespace std;
int main ()
{
cout << “Value of __LINE__ : ” << __LINE__ << endl;
cout << “Value of __FILE__ : ” << __FILE__ << endl;
cout << “Value of __DATE__ : ” << __DATE__ << endl;
cout << “Value of __TIME__ : ” << __TIME__ << endl;
return 0;
}
A. 5
B. runtime error
C. compile time error
D. details about your file
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Answer:-D. details about your fileExplanation
In this program, we are using the macros to print the information about the file. Output: $ g++ mac2.cpp $ a.out Value of __LINE__ : 5 Value of __FILE__ : mac1.cpp Value of __DATE__ : Oct 10 2012 Value of __TIME__ : 22:24:37Q 7. What will be the output of the following C++ code?
#include <iostream>
using namespace std;
#define SquareOf(x) x * x
int main()
{
int x;
cout << SquareOf(x + 4);
return 0;
}
A. 16
B. 64
C. compile time error
D. 75386824
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Answer:-D. 75386824Explanation
In this program, as we have not initialize the variable x, we will get a output of ending digit of 4. Output: $ g++ mac1.cpp $ a.out 75386824Q 8. What will be the output of the following C++ code?
#include <iostream>
using namespace std;
#define PR(id) cout << “The value of ” #id ” is “<<id
int main()
{
int i = 10;
PR(i);
return 0;
}
A. 10
B. 15
C. 20
D. 32
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Answer:-A. 10Explanation
In this program, we are just printing the declared values. Output: $ g++ mac.cpp $ a.out 10Q 9. What will be the output of the following C++ code?
#include <iostream>
using namespace std;
#define MAX 10
int main()
{
int num;
num = ++MAX;
cout << num;
return 0;
}
A. 9
B. 10
C. 15
D. compile time error
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Answer:-D. compile time errorExplanation
Macro Preprocessor only replaces occurance of macro symbol with macro symbol value, So we can’t increment the value.Q 10. What is the other name of the macro?
A. executed directive
B. scripted directive
C. link directive
D. executed & link directive
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