Inheritance Examples

Transcription

1 Example #1: Employee Class Hierarchy #ifndef EMPLOYEE_H_INCLUDED #define EMPLOYEE_H_INCLUDED #include <string> Inheritance Examples class employee public: // constructor employee(const std::string& name, const std::string& ssn); // output basic employee information void displayemployeeinfo(); // function with this prototype will exist in each derived class void payrollcheck(); protected: // maintain an employee's name and social // security number std::string empname; std::string empssn; private: int n; ; #endif // EMPLOYEE_H_INCLUDED ///////////////////////////////////////////////////////////////////////// #include "employee.h" #include <string> #include <iostream> employee::employee(const std::string& name, const std::string& ssn) empname = name; empssn = ssn; void employee::displayemployeeinfo() std::cout << "Name: " << empname << std::endl; std::cout << "Social Security Number: " << empssn << std::endl; void employee::payrollcheck() 1

2 #ifndef SALARYEMPLOYEE_H_INCLUDED #define SALARYEMPLOYEE_H_INCLUDED #include "employee.h" #include <string> // salaried employee "is an" employee with a monthly salary class salaryemployee : public employee public: // initialize Employee attributes and monthly salary salaryemployee(const std::string& name, const std::string& ssn, double sal); // update the monthly salary void setsalary(double sal); // call displayemployeeinfo from base class and add // information about the status (salaried) and weekly salary void displayemployeeinfo(); // cut a payroll check with the employee name, social security // number in angle brackets, and salary void payrollcheck(); private: // salary per pay period double salary; ; #endif // SALARYEMPLOYEE_H_INCLUDED ///////////////////////////////////////////////////////////////////////// #include "salaryemployee.h" #include <string> #include <iostream> salaryemployee::salaryemployee(const std::string& name, const std::string& ssn, double sal): employee(name,ssn) salary = sal; void salaryemployee::setsalary(double sal) salary = sal; void salaryemployee::displayemployeeinfo() std::cout.precision(10); employee::displayemployeeinfo(); std::cout << "Status: salaried employee" << std::endl; std::cout << "Salary per week $" << salary << std::endl; 2

3 void salaryemployee::payrollcheck() std::cout.precision(10); std::cout << "Pay " << empname << " (" << empssn << ") $" << salary << std::endl; ///////////////////////////////////////////////////////////////////////// #ifndef HOURLYEMPLOYEE_H_INCLUDED #define HOURLYEMPLOYEE_H_INCLUDED #include <string> #include "employee.h" // hourly employee "is an" employee paid by the hour class hourlyemployee : public employee public: // initialize Employee attributes, hourly pay rate // and hours worked hourlyemployee(const std::string& name, const std::string& ssn, double hp, double hw); // update the hourly pay and hours worked void sethourlypay(double hp); void sethoursworked(double hw); // call displayemployeeinfo from base class and output info // on hourly rate and scheduled hours void displayemployeeinfo(); void payrollcheck(); private: // pay based on hourly pay and hours worked double hourlypay; double hoursworked; ; #endif // HOURLYEMPLOYEE_H_INCLUDED ///////////////////////////////////////////////////////////////////////// #include "hourlyemployee.h" #include <iomanip> #include <iostream> hourlyemployee::hourlyemployee(const std::string& name, const std::string& ssn, double hp, double hw) : employee(name,ssn) hourlypay = hp; hoursworked = hw; 3

4 void hourlyemployee::sethourlypay(double hp) hourlypay = hp; void hourlyemployee::sethoursworked(double hw) hoursworked = hw; void hourlyemployee::displayemployeeinfo() std::cout.precision(10); employee::displayemployeeinfo(); std::cout << "Status: hourly employee" << std::endl; std::cout << "Payrate: $" << hourlypay << " per hour" << std::endl; std::cout << "Work schedule (hours per week) " << hoursworked << std::endl; void hourlyemployee::payrollcheck() std::cout.precision(10); std::cout << "Pay " << empname << " (" << empssn << ") $" << (hourlypay * hoursworked) << std::endl; ///////////////////////////////////////////////////////////////////////// #include <iostream> #include "employee.h" #include "hourlyemployee.h" #include "salaryemployee.h" int main() using namespace std; // declare an hourly employee hourlyemployee hemp("steve Howard"," ",7.50,40); // output only the base class information on Steve Howard hemp.employee::displayemployeeinfo(); cout << endl; // give Steve Howard a raise and output full set of information hemp.sethourlypay(10.00); hemp.displayemployeeinfo(); cout << endl; // provide a weekly check hemp.payrollcheck(); cout << endl; employee e = hemp; e.displayemployeeinfo(); cout << endl; 4

5 // declare an hourly employee salaryemployee semp("jane Doe"," ",2000); // output only the base class information on Steve Howard semp.employee::displayemployeeinfo(); cout << endl; // give Steve Howard a raise and output full set of information semp.displayemployeeinfo(); cout << endl; // provide a weekly check semp.payrollcheck(); cout << endl; e = semp; e.displayemployeeinfo(); cout << endl; return 0; ///////////////////////////////////////////////////////////////////////// Name: Steve Howard Social Security Number: Name: Steve Howard Social Security Number: Status: hourly employee Payrate: $10 per hour Work schedule (hours per week) 40 Pay Steve Howard ( ) $400 Name: Steve Howard Social Security Number: Name: Jane Doe Social Security Number: Name: Jane Doe Social Security Number: Status: salaried employee Salary per week $2000 Pay Jane Doe ( ) $2000 Name: Jane Doe Social Security Number:

6 Example #1: Geometric Object Class Hierarchy #ifndef SHAPE_H #define SHAPE_H #include <fstream> // the graphics base class. maintains the base point and fill // color. has functions to access and change these attributes. // the graphics classes that draw specific figures inherit // this class class shape public: shape(double x = 0, double y = 0, double r = 0, double g = 0, double b = 0); // the arguments initialize the base point (x,y) and the fill color c virtual ~shape(); // virtual destructor may be necessary for derived class double getx(); // returns the x coordinate of the base point double gety(); // returns the y coordinate of the base point void move(double x, double y); // repositions the base point to the new coordinates (x,y) void setcolor(double r, double g, double b); // set the fill color of the figure to the value c from the // color palette virtual void draw(std::ofstream &svgfile) = 0; // draw the shape. must be implemented in a derived class virtual void update(std::ofstream &svgfile); // update the shape protected: // location of the base point double basex, basey; ; // color of the shape double red; double green; double blue; #endif // GEOMETRIC_FIGURES_BASE 6

7 #include "shape.h" // initialize basepoint coordinates and color shape::shape(double x, double y, double r, double g, double b) basex = x; basey = y ; red = r; green = g; blue = b; shape::~shape() double shape::getx() return basex; double shape::gety() return basey; void shape::setcolor(double r, double g, double b) red = r; green = g; blue = b; void shape::move(double x, double y) basex = x; basey = y; void shape::update(std::ofstream &svgfile) draw(svgfile); 7

8 #ifndef CIRCSH_H #define CIRCSH_H #include "shape.h" #include <fstream> // declaration of circleshape class with base class shape class circleshape : public shape public: circleshape(double x = 0.0, double y = 0.0, double rad = 0.0, double r = 0, double g = 0, double b = 0); // arguments for the base point, radius and color double getradius(); void setradius(double r); // retrieve or set the radius virtual void draw(std::ofstream &svgfile); // draw the circle private: double radius; // radius of the circle ; #endif // CIRCLESHAPE_CLASS 8

9 #include "circsh.h" circleshape::circleshape(double x, double y, double rad, double r, double g, double b): shape(x,y,r,g,b) radius = rad; // read the radius value; return value of private radius data double circleshape::getradius() return radius; // change the radius value of the current object void circleshape::setradius(double r) radius = r; // assign r as the new radius // draw the circleshape with center at (x,y), given radius // and color void circleshape::draw(std::ofstream &svgfile) using namespace std; int r = (int)(red*255); int g = (int)(green*255); int b = (int)(blue*255); svgfile << "<circle cx=\"" << basex << "\" cy=\"" << basey << "\" r=\"" << radius << "\" style=\"fill:rgb(" << r << "," << g << "," << b << "); stroke:rgb(" << r << "," << g << "," << b << "); stroke-width:0\"/>" << endl; 9

10 #ifndef LINESH_H #define LINESH_H #include "shape.h" // declaration of lineshape class with base class shape class lineshape: public shape public: lineshape(double x = 0.0, double y = 0.0, double x2 = 0.0, double y2 = 0.0, double r = 0, double g = 0, double b = 0); // constructor. has arguments for base point, // the second point on the line and the color // line data access member functions double getendx(); double getendy(); void setendpoint(double x, double y); // retrieve or set length of the second point virtual void draw(std::ofstream &svgfile); // draw the line private: double endx, endy; // second point on the line ; #endif // LINESHAPE_CLASS 10

11 #include "linesh.h" lineshape::lineshape(double x, double y, double x2, double y2, double r, double g, double b): shape(x,y,r,g,b) endx = x2; endy = y2; double lineshape::getendx() return endx; double lineshape::getendy() return endy; // change the end point. must recompute length void lineshape::setendpoint(double x, double y) endx = x; endy = y; void lineshape::draw(std::ofstream &svgfile) using namespace std; int r = (int)(red*255); int g = (int)(green*255); int b = (int)(blue*255); svgfile << "<g stroke=\"rgb(" << r << "," << g << "," << b << ")\" >"; svgfile << "<line x1=\"" << basex << "\" y1=\"" << basey << "\" x2=\"" << endx << "\" y2=\"" << endy << "\" stroke-width=\"1\" />"; svgfile << "</g>" << endl; 11

12 #ifndef RECTSH_H #define RECTSH_H #include "shape.h" // declaration of rectshape class with base class shape class rectshape: public shape public: rectshape(double x = 0.0, double y = 0.0, double w = 0.0, double h = 0.0, double r = 0, double g = 0, double b = 0); // constructor. has parameters for the base point, // height, width and color double getheight(); double getwidth(); void setsides(double w, double h); // retrieve or set rectangle dimensions virtual void draw(std::ofstream &svgfile); // draw the rectangle private: // rectangle dimensions double height; double width; ; #endif // RECTANGLESHAPE_CLASS 12

13 #include "rectsh.h" rectshape::rectshape(double x, double y, double w, double h, double r, double g, double b): shape(x,y,r,g,b) width = w; height = h; double rectshape::getheight() return height; double rectshape::getwidth() return width; void rectshape::setsides(double w, double h) height = h; width = w; void rectshape::draw(std::ofstream &svgfile) using namespace std; int r = (int)(red*255); int g = (int)(green*255); int b = (int)(blue*255); svgfile << "<rect x=\"" << basex << "\" y=\"" << basey << "\" width=\"" << width << "\" height=\"" << height << "\" style=\"fill:rgb(" << r << "," << g << "," << b << "); stroke:rgb(" << r << "," << g << "," << b << "); stroke-width:0\"/>" << endl; 13

14 #ifndef TEXTSH_H #define TEXTSH_H #include <string> #include "shape.h" class textshape: public shape public: textshape(double x = 0.0, double y = 0.0, const std::string& s ="", double r = 0, double g = 0, double b = 0); // constructor. has arguments for the base point, // text string and color std::string gettext(); void settext(const std::string& s); // retrieve or set the text virtual void draw(std::ofstream &svgfile); // draw the text private: std::string text; // text to draw ; #endif // TEXT_SHAPE_CLASS 14

15 #include "textsh.h" textshape::textshape(double x, double y, const std::string& s, double r, double g, double b): shape(x,y,r,g,b) text = s; std::string textshape::gettext() return text; void textshape::settext(const std::string& s) text = s; void textshape::draw(std::ofstream &svgfile) using namespace std; int r = (int)(red*255); int g = (int)(green*255); int b = (int)(blue*255); svgfile << "<text x=\"" << basex << "\" y=\"" << basey << "\" font-family=\"verdana\" font-size=\"20\" fill=\" rgb(" << r << "," << g << "," << b << ") \" >"; svgfile << text; svgfile << "</text>" << endl; 15

16 #ifndef POLYSH_H #define POLYSH_H #include <vector> #include <cmath> #include "shape.h" // declaration of polygonshape class with base class shape class polyshape : public shape public: polyshape(double x = 0.0, double y = 0.0, int n = 4, double len = 0.0, double r = 0, double g = 0, double b = 0); // constructor. has arguments for the base point, // number of sides, the length of each side and the // color double getlength(); void setlength(double len); // retrieve or set length of a side int getn(); void setn(int numsides); // retrieve or set number of sides virtual void draw(std::ofstream &svgfile); // draw the polygon private: int numsides; // number of sides double length; // length of each side std::vector<double> point_x; std::vector<double> point_y; // x and y-coordinates of the vertices ; void buildpoints(); // construct the vertices #endif // POLYGONSHAPE_CLASS 16

17 #include "polysh.h" void polyshape::buildpoints() int side; double theta, d; const double PI = ; const double DELTA_THETA = (2.0*PI)/numSides; // allocate space for the numsides coordinates point_x.resize(numsides); point_y.resize(numsides); d = length/(2.0*sin(pi/numsides)); theta = 0.0; for(side = 0; side < numsides; side++) point_x[side] = basex + d*cos(theta); point_y[side] = basey - d*sin(theta); theta += DELTA_THETA; // initialize base class, the number of sides // and the length of each side polyshape::polyshape(double x, double y, int n, double len, double r, double g, double b): shape(x,y,r,g,b) numsides = n; length = len; double polyshape::getlength() return length; // change the length of a side void polyshape::setlength(double len) length = len; int polyshape::getn() return numsides; void polyshape::setn(int n) numsides = n; 17

18 void polyshape::draw(std::ofstream &svgfile) using namespace std; int r = (int)(red*255); int g = (int)(green*255); int b = (int)(blue*255); buildpoints(); svgfile << "<polygon "; svgfile << "style=\"fill:rgb(" << r << "," << g << "," << b << "); stroke:rgb(" << r << "," << g << "," << b << "); stroke-width:0\""; svgfile << " points=\""; for(int side = 0; side < numsides; side++) svgfile << (int)point_x[side] << "," << (int)point_y[side] << " "; svgfile << "\" />" << endl; 18

19 #include <iostream> #include <iomanip> #include <fstream> #include "shape.h" #include "rectsh.h" #include "circsh.h" #include "linesh.h" #include "textsh.h" #include "polysh.h" void WriteFrontMatter(std::ofstream &svgfile, int width, int height) using namespace std; svgfile << "<?xml version=\"1.0\" standalone=\"no\"?>" << endl; svgfile << "<!DOCTYPE svg PUBLIC \"-//W3C//DTD SVG 1.1//EN\" \" << endl; svgfile << "<svg width=\"" << width << "\" height=\"" << height << "\" version=\"1.1\" xmlns=\" << endl; void WriteBackMatter(std::ofstream &svgfile) using namespace std; svgfile << "</svg>" << endl; int main() using namespace std; // Example Image 1 ofstream svgfile; svgfile.open("svg_image1.svg"); WriteFrontMatter(svgfile, 500, 400); circleshape circ1(100, 100, 100, 1, 0, 0); circ1.draw(svgfile); circ1.move(200, 150); circ1.setradius(25); circ1.setcolor(0, 1, 0); circ1.draw(svgfile); rectshape rect1(70, 150, 25, 130, 0, 0, 1); rect1.draw(svgfile); lineshape line1(0,0,300,300,0,0,0); line1.draw(svgfile); polyshape poly1(250,200, 5, 100, 1, 0, 1); poly1.draw(svgfile); 19

20 textshape text1(0,300,"hi There", 0, 0, 0); text1.draw(svgfile); WriteBackMatter(svgfile); svgfile.close(); // Example Image 2 svgfile.open("svg_image2.svg"); WriteFrontMatter(svgfile, 600, 400); shape *fptr[8]; fptr[0] = new circleshape(100, 100, 83, 1, 1, 0); fptr[1] = new rectshape(70, 150, 25, 130, 0, 0, 1); fptr[2] = new lineshape(0,0,300,300,0,1,0); fptr[3] = new polyshape(250,200, 17, 30, 1, 0, 1); fptr[4] = new textshape(0,100,"hi There", 0, 0, 0); fptr[5] = new lineshape(50,70,200,300,0,0,1); fptr[6] = new lineshape(20,200,300,10,0,0,0); fptr[7] = new textshape(40,200,"morphing is so cool!", 0, 0, 0); for (int i = 0; i < 8; i++) (*fptr[i]).draw(svgfile); WriteBackMatter(svgfile); svgfile.close(); return 0; 20

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