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By Root 1162 0

you should make them protected and provide public getter and setter methods. You should also try to minimize private data members, and instead opt for protected data members so that you don’t prevent subclasses from using them. You can make the copy constructor and assignment operator private to prevent assignment and pass-by-value.

Next, here is the implementation, including the initialization of the static data member:

#include "Simple.h"

int Simple::sStaticInt = 0; // Initialize static data member.

Simple::Simple()

{

// Implementation of constructor

}

Simple::~Simple()

{

// Implementation of destructor

}

void Simple::publicMethod()

{

// Implementation of public method

}

Code snippet from Simple\Simple.cpp

Note that with C++11, you can initialize sStaticInt within the class definition as explained in Chapter 6.

Chapters 6 and 7 provide all the details for writing your own classes.

... Subclass an Existing Class

To subclass, you declare a new class that is a public extension of another class. Here is the definition for a sample subclass called SubSimple:

#ifndef _subsimple_h_

#define _subsimple_h_

#include "Simple.h"

// A subclass of the Simple class

class SubSimple : public Simple

{

public:

SubSimple(); // Constructor

virtual ~SubSimple(); // Destructor

virtual void publicMethod(); // Overridden method

virtual void anotherMethod(); // Added method

};

#endif

Code snippet from Simple\SubSimple.h

The implementation:

#include "SubSimple.h"

SubSimple::SubSimple() : Simple()

{

// Implementation of constructor

}

SubSimple::~SubSimple()

{

// Implementation of destructor

}

void SubSimple::publicMethod()

{

// Implementation of overridden method

}

void SubSimple::anotherMethod()

{

// Implementation of added method

}

Code snippet from Simple\SubSimple.cpp

Consult Chapter 8 for details on inheritance techniques.

... Throw and Catch Exceptions

If you’ve been working on a team that doesn’t use exceptions (for shame!) or if you’ve gotten used to Java-style exceptions, the C++ syntax may escape you. Here’s a refresher, which uses the built-in exception class std::runtime_error. In most large programs, you will write your own exception classes.

#include

#include

void throwIf(bool inShouldThrow) throw (std::runtime_error)

{

if (inShouldThrow) {

throw std::runtime_error("Here's my exception");

}

}

int main()

{

try {

throwIf(false); // doesn't throw

throwIf(true); // throws!

} catch (const std::runtime_error& e) {

std::cerr << "Caught exception: " << e.what() << std::endl;

}

return 0;

}

Code snippet from Exceptions\Exceptions.cpp

Chapter 10 discusses exceptions in more detail.

... Read from a File

Complete details for file input are included in Chapter 15. Here is a quick sample program for file reading basics. This program reads its own source code and outputs it one token at a time.

#include

#include

#include

using namespace std;

int main()

{

ifstream inFile("FileRead.cpp");

if (inFile.fail()) {

cerr << "Unable to open file for reading." << endl;

return 1;

}

string nextToken;

while (inFile >> nextToken) {

cout << "Token: " << nextToken << endl;

}

inFile.close();

return 0;

}

Code snippet from FileRead\FileRead.cpp

... Write to a File

The following program outputs a message to a file, then reopens the file and appends another message. Additional details can be found in Chapter 15.

#include

#include

using namespace std;

int main()

{

ofstream outFile("FileWrite.out");

if (outFile.fail()) {

cerr << "Unable to open file for writing." << endl;

return 1;

}

outFile << "Hello!" << endl;

outFile.close();

ofstream appendFile("FileWrite.out", ios_base::app);

if (appendFile.fail()) {

cerr << "Unable to open file for appending." << endl;

return 2;

}

appendFile << "Append!" << endl;

appendFile.close();

return 0;

}

Code snippet from FileWrite\FileWrite.cpp

... Write a Template Class

Template syntax is one of the messiest parts of the C++ language.