View source for Basics of C/C++ Programming Practice 7 Code

====== Shape ======

<div class="mw-collapsible mw-collapsed">shape.h
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  #pragma once
  
  class Shape
  {
  protected:
    int numAngles;
  
  public:
    Shape(int angles);
    virtual ~Shape();
  
    int getNumAngles();
  
    virtual double area() = 0;
  };
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<div class="mw-collapsible mw-collapsed">shape.cpp
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  #include "Shape.h"
  
  Shape::Shape(int angles) : numAngles(angles)
  {
  }
  
  Shape::~Shape()
  {
  }
  
  int Shape::getNumAngles()
  {
    return numAngles;
  }
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====== Circle ======

<div class="mw-collapsible mw-collapsed">circle.h
<div class="mw-collapsible-content">
  #pragma once
  #include "Shape.h"
  
  class Circle : public Shape
  {
    double radius;
  public:
    Circle(double newRadius);  
    ~Circle();
  
    virtual double area() override;
  };
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<div class="mw-collapsible mw-collapsed">circle.cpp
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  #include "Circle.h"
  #include <cmath>
  
  Circle::Circle(double newRadius) : Shape(0), radius(newRadius)
  {
  }
  
  Circle::~Circle()
  {
  }
  
  double Circle::area()
  {
    return 3.1415 * pow(radius, 2);
  }
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====== Rectangle ======

<div class="mw-collapsible mw-collapsed">rectangle.h
<div class="mw-collapsible-content">
  #pragma once
  #include "Shape.h"
  
  class Rectangle : public Shape
  {
    double width;
    double height;
  public:
    Rectangle(double newWidth, double newHeight);
    ~Rectangle();
  
    virtual double area() override;
  };
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<div class="mw-collapsible mw-collapsed">rectangle.cpp
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  #include "Rectangle.h"
  
  Rectangle::Rectangle(double newWidth, double newHeight)
    : Shape(4)
    , width(newWidth)
    , height(newHeight)
  {
  }
  
  Rectangle::~Rectangle()
  {
  }
  
  double Rectangle::area()
  {
    return width * height;
  }
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====== main ======

<div class="mw-collapsible mw-collapsed">main.cpp
<div class="mw-collapsible-content">
  #include <memory>
  #include <vector>
  #include <iostream>
  #include "Circle.h"
  #include "Rectangle.h"
  
  int main()
  {
    std::vector<std::unique_ptr<Shape>> shapes;
    shapes.push_back(std::make_unique<Rectangle>(2, 3));
    shapes.push_back(std::make_unique<Circle>(2));
  
    double totalArea = 0;
    for (std::unique_ptr<Shape>& shape : shapes)
    {
      std::cout << shape->getNumAngles() << std::endl;
    }
  
    return 0;
  }
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