Array MCQ in C++ - Sanfoundry

This section on C++ interview questions and answers focuses on “Arrays”. 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 “Arrays” along with answers, explanations and/or solutions:

1. Which of the following correctly declares an array?
a) int array[10];
b) int array;
c) array{10};
d) array array[10];
View Answer

Answer: a
Explanation: Because array variable and values need to be declared after the datatype only.

2. What is the index number of the last element of an array with 9 elements?
a) 9
b) 8
c) 0
d) Programmer-defined
View Answer

Answer: b
Explanation: Because the first element always starts at 0. So it is on 8 position.

3. What is the correct definition of an array?
a) An array is a series of elements of the same type in contiguous memory locations
b) An array is a series of element
c) An array is a series of elements of the same type placed in non-contiguous memory locations
d) An array is an element of the different type
View Answer

Answer: a
Explanation: Correct definition of an array is An array is a series of elements of the same type in contiguous memory locations.

4. Which of the following accesses the seventh element stored in array?
a) array[6];
b) array[7];
c) array(7);
d) array;
View Answer

Answer: a
Explanation: The array location starts from zero, So it can accessed by array[6].

5. Which of the following gives the memory address of the first element in array?
a) array[0];
b) array[1];
c) array(2);
d) array;
View Answer

Answer: d
Explanation: To get the address of ith index of an array, we use following syntax (arr + i). So as we need address of first index we will use (arr + 0) equivalent to arr.

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

```
    #include <stdio.h>
```
```
    #include<iostream>
```
```
    using namespace std;
```

    int array1[] = {1200, 200, 2300, 1230, 1543};

    int array2[] = {12, 14, 16, 18, 20};

```
    int temp, result = 0;
```
```
    int main()
```
```
    {
```

        for (temp = 0; temp < 5; temp++)

```
        {
```
```
            result += array1[temp];
```
```
        }
```

        for (temp = 0; temp < 4; temp++)

```
        {
```
```
            result += array2[temp];
```
```
        }
```
```
        cout << result;
```
```
        return 0;
```
```
    }
```

a) 6553
b) 6533
c) 6522
d) 12200
View Answer

Answer: b
Explanation: In this program we are adding every element of two arrays except the last element of array2. Finally, we got output as 6533.
Output:

$ g++ array.cpp
$ a.out
6533

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

```
    #include <stdio.h>
```
```
    #include<iostream>
```
```
    using namespace std;
```
```
    int main ()
```
```
    {
```

        int array[] = {0, 2, 4, 6, 7, 5, 3};

```
        int n, result = 0;
```
```
        for (n = 0; n < 8; n++) 
```
```
        {
```
```
            result += array[n];
```
```
        }
```
```
        cout << result;
```
```
        return 0;
```
```
    }
```

a) 25
b) 26
c) 27
d) 21
View Answer

Answer: c
Explanation: We are adding all the elements in the array and printing it. Total elements in the array is 7, but our for loop will go beyond 7 and add a garbage value.

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

```
    #include <stdio.h>
```
```
    #include<iostream>
```
```
    using namespace std;
```
```
    int main()
```
```
    {
```
```
        int a = 5, b = 10, c = 15;
```
```
        int arr[3] = {&a, &b, &c};
```
```
        cout << *arr[*arr[1] - 8];
```
```
        return 0;
```
```
    }
```

a) 15
b) 18
c) garbage value
d) compile time error
View Answer

Answer: d
Explanation: The conversion is invalid in this array. So it will arise error. The following compilation error will be raised:
cannot convert from ‘int *’ to ‘int’
This is because &a, &b and &c represent int* whereas the array defined is of int type.

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