Exercises

1.

Complete the code by creating a Point p1 that represents (3, 4.5).

2.

The existing code will make a point p1 at (4, 3). Shift it so it is at (1, 1).

3.

The existing code will make a point p1. Make a point p2 that has x and y value that are 1 more than the values for p1.

4.

Add a definition for the getPerimeter function in Rectangle. Your code will be inside the class.

5.

Add a definition for the getArea function that is declared in Rectangle. Your code will be outside the class, so you need to use the scope resolution operator.

6.

Add a definitions for the 2-arg constructor You are defining it outside of the class. Check the comment in the class for how it should behave.

#include <iostream>
#include <stdexcept>
using namespace std;

class Rectangle {
public:
    Rectangle() {
      // nothing to do
    }

/**
     * @brief Construct a new Rectangle object
     * 
     * If width or height is negative, throw a logic_error
     */
    Rectangle(double width, double height);

double getArea();

void setWidth(double width) {
        m_width = width;
    }
    void setHeight(double height) {
        m_height = height;
    }

double getWidth() {
        return m_width;
    }
    double getHeight() {
        return m_height;
    }

void scale(double scaleFactor);

private:
    double m_width = 0;
    double m_height = 0;
};

^^^!

//write your code here (it is outside the class)
===!

#define DOCTEST_CONFIG_IMPLEMENT_WITH_MAIN
#include "doctest.h"

TEST_CASE("Test 2-arg cosntructor") {
    Rectangle r1(3, 4);
    CHECK(r1.getWidth() == doctest::Approx(3));
    CHECK(r1.getHeight() == doctest::Approx(4));

Rectangle r2(7, 1.4);
    CHECK(r2.getWidth() == doctest::Approx(7));
    CHECK(r2.getHeight() == doctest::Approx(1.4));

// Make anonymous rectangles with negative value and check that exception is thrown
    CHECK_THROWS_AS(Rectangle(3, -4), logic_error);
    CHECK_THROWS_AS(Rectangle(-2, 5), logic_error);
}

Hint.

Section 10.10

7.

Add a definition for the scale function so the code passes the test. You are defining it outside of the class. Check the comment in the class for tips on how it should behave.

#include <iostream>
#include <stdexcept>
using namespace std;

class Rectangle {
public:
    Rectangle() {
      // nothing to do
    }

Rectangle(double width, double height);

double getArea();

void setWidth(double width) {
        m_width = width;
    }
    void setHeight(double height) {
        m_height = height;
    }

double getWidth() {
        return m_width;
    }
    double getHeight() {
        return m_height;
    }

/**
     * @brief Multiply the width and height of the rectangle by a scale factor.
     * 
     * @param scaleFactor amount to scale the rectangle by. If negative, no scaling is done.
     */
    void scale(double scaleFactor);

private:
    double m_width = 0;
    double m_height = 0;
};

^^^!

//write your code here (it is outside the class)
===!

#define DOCTEST_CONFIG_IMPLEMENT_WITH_MAIN
#include "doctest.h"

TEST_CASE("Test scale") {
    Rectangle r1;
    r1.setWidth(3);
    r1.setHeight(4);
    
    r1.scale(3);
    CHECK(r1.getWidth() == doctest::Approx(9));
    CHECK(r1.getHeight() == doctest::Approx(12));

r1.scale(0.5);
    CHECK(r1.getWidth() == doctest::Approx(4.5));
    CHECK(r1.getHeight() == doctest::Approx(6));

r1.scale(-2);
    CHECK(r1.getWidth() == doctest::Approx(4.5));
    CHECK(r1.getHeight() == doctest::Approx(6));
}

Exercises 16.16 Exercises

1.

2.

3.

4.

5.

6.

7.