Parameterized constructor in C++ - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a parameterized constructor for class Car.

C++

class Car {
public:
    int year;
    Car([1]) {
        year = y;
    }
};

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Aint y

Byear

CCar()

Dvoid y

Attempts:

3 left

💡 Hint

Common Mistakes

Using the class name as a parameter type

Forgetting to specify the parameter type

Using void as a parameter type

The parameterized constructor takes an integer parameter y to initialize the year attribute.

2fill in blank

medium

Complete the constructor initialization list to set the member variable.

C++

class Book {
    int pages;
public:
    Book(int p) : [1] {}
};

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Apages = p

Bpages(p)

Cp(pages)

Dpages:p

Attempts:

3 left

💡 Hint

Common Mistakes

Using assignment inside the initialization list

Reversing the order of member and parameter

Using colon instead of parentheses

The constructor initialization list uses pages(p) to initialize the member variable pages with the parameter p.

3fill in blank

hard

Fix the error in the parameterized constructor declaration.

C++

class Student {
    int id;
public:
    Student([1]) {
        id = i;
    }
};

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Aint i

Bi int

Cint

Dvoid i

Attempts:

3 left

💡 Hint

Common Mistakes

Writing the variable name before the type

Omitting the variable name

Using void as a parameter type

The constructor parameter must specify the type followed by the variable name, like int i.

4fill in blank

hard

Fill both blanks to complete the constructor that initializes two member variables.

C++

class Point {
    int x, y;
public:
    Point(int a, int b) : [1], [2] {}
};

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Ax(a)

Ba(x)

Cy(b)

Db(y)

Attempts:

3 left

💡 Hint

Common Mistakes

Reversing member and parameter names

Using assignment instead of initialization list

Omitting one of the member initializations

The constructor uses the initialization list to set x with a and y with b.

5fill in blank

hard

Fill all three blanks to complete the constructor initializing three members with parameters.

C++

class Rectangle {
    int width, height, area;
public:
    Rectangle(int w, int h) : [1], [2], [3] {
        area = width * height;
    }
};

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Awidth(w)

Bheight(h)

Carea(0)

Darea(w*h)

Attempts:

3 left

💡 Hint

Common Mistakes

Initializing area with w*h in the list (should be done in body)

Mixing parameter and member names

Forgetting to initialize all members

The constructor initializes width and height with parameters w and h, and sets area to 0 initially before calculating it in the constructor body.