250+ TOP MCQs on Subscripting and Answers

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This section on C++ interview questions and answers on “Subscripting”. One shall practice these interview questions to improve their C++ programming skills needed for various interviews (campus interviews, walkin interviews, company interviews), placements, 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 detailed explanation of the answers which helps in better understanding of C++ concepts.

Here is a listing of C++ interview questions on “Subscripting” along with answers, explanations and/or solutions:

1. subscript operator is used to access which elements?
a) string
b) char
c) array
d) float
Answer: c
Clarification: To access any element of an array we use following syntax array[i], where i is called subscript representing the ith element of an array, whereas no such cases in char and strings.

2. How many arguments will the subscript operator will take for overloading?
a) 1
b) 2
c) 0
d) as many as possible
Answer: a
Clarification: The subscript operator overload takes only one argument, but it can be of any type.

3. Pick out the correct statement.
a) subscript operator has a higher precedence than the assignment operator
b) subscript operator has a lower precedence than the assignment operator
c) subscript operator is used with string elements
d) subscript operator is used with char elements
Answer: a
Clarification: Subscription operator has more precedence otherwise if that is not the case then the statement var = arr[i] will be meaningless and will have no effect.

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

  1.     #include 
  2.     using namespace std;
  3.     const int SIZE = 10;
  4.     class safe
  5.     {
  6.         private:
  7.         int arr[SIZE];
  8.         public:
  9.         safe()
  10.         {
  11.             register int i;
  12.             for (i = 0; i < SIZE; i++)
  13.             {
  14.                 arr[i] = i;
  15.             }
  16.         }
  17.         int &operator[](int i)
  18.         {
  19.             if (i > SIZE)
  20.             {
  21.                 cout << "Index out of bounds" <<endl;
  22.                 return arr[0];
  23.             }
  24.             return arr[i];
  25.         }
  26.     };
  27.     int main()
  28.     {
  29.         safe A;
  30.         cout << A[5];
  31.         cout  << A[12];
  32.         return 0;
  33.     }

a) 

5Index out of bounds
 0

b) 40
c) 50
d) 51
Answer: a
Clarification: In this program, We are returning the elements in the specified array location and if it is out of bound means it will return the first element.
Output:

$ g++ sub.cpp
$ a.out
5Index out of bounds
0

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

  1.     #include 
  2.     using namespace std;
  3.     class numbers
  4.     {
  5.         private:
  6.         int m_nValues[10];
  7.         public:
  8.         int& operator[] (const int nValue);
  9.     };
  10.     int& numbers::operator[](const int nValue)
  11.     {
  12.         return m_nValues[nValue];
  13.     }
  14.     int main()
  15.     {
  16.         numbers N;
  17.         N[5] = 4;
  18.         cout <<  N[5];
  19.         return 0;
  20.     }

a) 5
b) 4
c) 3
d) 6
Answer: b
Clarification: In this program, We are getting the values and returning it by overloading the subscript operator.
Output:

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

  1.     #include 
  2.     using namespace std;
  3.     const int limit = 4;
  4.     class safearray
  5.     {
  6.         private:
  7.         int arr[limit];
  8.         public:
  9.         int& operator [](int n)
  10.         {
  11.             if (n == limit - 1)
  12.             {
  13.                 int temp;
  14.                 for (int i = 0; i < limit; i++)
  15.                 {
  16.                     if (arr[n + 1] > arr[n])
  17.                     {
  18.                         temp = arr[n];
  19.                         arr[n] = arr[n + 1];
  20.                         arr[n + 1] = temp;
  21.                     }     
  22.                 }  
  23.             }
  24.             return arr[n];
  25.         }
  26.     };
  27.     int main()
  28.     {
  29.         safearray sa1;
  30.         for(int j = 0; j < limit; j++)
  31.             sa1[j] = j*10;
  32.         for(int j = 0; j < limit; j++)
  33.         {
  34.             int temp = sa1[j];
  35.             cout << "Element " << j << " is " << temp;
  36.         }
  37.         return 0;
  38.     }

a) 0102030
b) 1020300
c) 3020100
d) error
Answer: a
Clarification: In this program, we are returning the array element by the multiple of 10.
Output:

$ g++ sub2.cpp
$ a.out
0102030