4elist2004.cpp

《21天学通C＋＋》附盘的原代码。书上的每个例子在这里都有相应的C语言程序。

#include <iostream>
using namespace std;

const int DefaultSize = 10;

class Array
{
public:
	// constructors
	Array(int itsSize = DefaultSize);
	Array(const Array &rhs);
	~Array() { delete [] pType;}

	// operators
	Array& operator=(const Array&);
	int& operator[](int offSet);
	const int& operator[](int offSet) const;

	// accessors
	int GetitsSize() const { return itsSize; }

	// friend function
	friend ostream& operator<< (ostream&, const Array&);

	// define the exception classes
	class xBoundary {};
	class xSize
	{
	public:
		xSize(int size):itsSize(size) {}
		~xSize(){}
		int GetSize() { return itsSize; }
	private:
		int itsSize;
	};

	class xTooBig : public xSize
	{
	public:
		xTooBig(int size):xSize(size){}
	};

	class xTooSmall : public xSize
	{
	public:
		xTooSmall(int size):xSize(size){}
	};

	class xZero  : public xTooSmall
	{
	public:
		xZero(int size):xTooSmall(size){}
	};

	class xNegative : public xSize
	{
	public:
		xNegative(int size):xSize(size){}
	};

private:
	int *pType;
	int  itsSize;
};


Array::Array(int size):
itsSize(size)
{
	if (size == 0)
		throw xZero(size);
	if (size > 30000)
		throw xTooBig(size);
	if (size <1)
		throw xNegative(size);
	if (size < 10)
		throw xTooSmall(size);

	pType = new int[size];
	for (int i = 0; i<size; i++)
		pType[i] = 0;
}


int& Array::operator[] (int offSet)
{
	int size = GetitsSize();
	if (offSet >= 0 && offSet < GetitsSize())
		return pType[offSet];
	throw xBoundary();
	return pType[0];
}

const int& Array::operator[] (int offSet) const
{
	int size = GetitsSize();
	if (offSet >= 0 && offSet < GetitsSize())
		return pType[offSet];
	throw xBoundary();
	return pType[0];
}

int main()
{
	try
	{
		Array intArray(9);
		for (int j = 0; j< 100; j++)
		{
			intArray[j] = j;
			cout << "intArray[" << j << "] okay..." << endl;
		}
	}
	catch (Array::xBoundary)
	{
		cout << "Unable to process your input!\n";
	}
	catch (Array::xZero theException)
	{
		cout << "You asked for an Array of zero objects!" << endl;
		cout << "Received " << theException.GetSize() << endl;
	}
	catch (Array::xTooBig theException)
	{
		cout << "This Array is too big..." << endl;
		cout << "Received " << theException.GetSize() << endl;
	}
	catch (Array::xTooSmall theException)
	{
		cout << "This Array is too small..." << endl;
		cout << "Received " << theException.GetSize() << endl;
	}
	catch (...)
	{
		cout << "Something went wrong, but I've no idea what!\n";
	}
	cout << "Done.\n";
	return 0;
}