1.头文件声明
#ifndef CMATRIX_H
#define CMATRIX_H
#include <iostream>
using namespace std;
class CMatrix
{
public:
//函数的构建
CMatrix();
CMatrix(int nRow, int nCol, double* pData = NULL);
CMatrix(const CMatrix& m);
CMatrix(const char* strPath);
~CMatrix();
//函数的创建删除和设置
bool Create(int nRow, int nCol, double* pData = NULL);
void Set(int nRow, int nCol, double dVale);
void Release();
//友元函数,访问私有变量
friend istream& operator>>(istream& is, CMatrix& m);
friend ostream& operator<<(ostream& os, const CMatrix& m);
//操作符重载
CMatrix& operator =(const CMatrix& m);
CMatrix& operator +=(const CMatrix& m);
double& operator[](int nIndex);
double& operator()(int nRow, int nCol);
bool operator ==(const CMatrix& m);
bool operator !=(const CMatrix& m);
operator double();
//私有变量
private:
int m_nRow;
int m_nCol;
double* m_pData;
};
CMatrix operator+(const CMatrix& m1, const CMatrix& m2);
//内联函数
inline void CMatrix::Set(int nRow, int nCol, double dVal)
{
m_pData[nRow * m_nCol + nCol] = dVal;
}
#endif
2.函数的实现
(1)构造器。 本次实验提供四个构造器,下面四个构造器分别为无参构造器,有参构造器,已经复制已有的类创建新的类,通过文件读入构造。
CMatrix::CMatrix() :m_nRow(0), m_nCol(0), m_pData(0)
{
}
CMatrix::CMatrix(int nRow, int nCol, double* pData) : m_pData(0)
{
Create(nRow, nCol, pData);
}
CMatrix::CMatrix(const CMatrix& m) : m_pData(0)
{
*this = m;
}
CMatrix::CMatrix(const char* strPath)
{
m_pData = 0;
m_nRow = m_nCol = 0;
ifstream cin(strPath);
cin >> *this;
}
(2)下面为对象的创建,删除和析构函数。析构函数为当对象结束其生命周期,系统自动执行析构函数。例如在建立对象时用new开辟了一片内存空间,delete会自动调用析构函数后释放内存
bool CMatrix::Create(int nRow, int nCol, double* pData)
{
Release();
m_pData = new double[nRow * nCol];
m_nRow = nRow;
m_nCol = nCol;
if (pData != NULL)
{
memcpy(m_pData, pData, nRow * nCol * sizeof(double));
return true;
}
else {
return false;
}
}
void CMatrix::Release()
{
if (m_pData!=NULL)
{
delete []m_pData;
m_pData = NULL;
}
m_nRow = m_nCol = 0;
}
CMatrix::~CMatrix()
{
Release();
}
(3)运算符重载:下面分别对‘=’,‘+=’,‘+’,‘==’,‘!=’进行重载
CMatrix& CMatrix::operator=(const CMatrix& m)
{
if (this != &m)
{
Create(m.m_nRow, m.m_nCol, m.m_pData);
}
return *this;
}
CMatrix& CMatrix::operator+=(const CMatrix& m)
{
assert(m_nRow == m.m_nRow && m_nCol == m.m_nCol);
for (int i = 0; i < m_nRow * m_nCol; i++)
{
m_pData[i] += m.m_pData[i];
}
return *this;
}
CMatrix operator+(const CMatrix& m1, const CMatrix& m2)
{
CMatrix m3(m1);
m3 += m2;
return m3;
}
bool CMatrix::operator == (const CMatrix& m)
{
if (!(m_nRow == m.m_nRow && m_nCol == m.m_nCol))
{
return false;
}
for (int i = 0; i < m_nRow * m_nCol; i++)
{
if (m_pData[i] != m.m_pData[i])
{
return false;
}
}
return true;
}
bool CMatrix::operator !=(const CMatrix& m)
{
return !((*this) == m);
}
(4)操作符重载:下面分别对‘[]’,‘()’,‘<<’,‘>>'进行重载
double& CMatrix::operator[](int nIndex)
{
assert(nIndex < m_nRow* m_nCol);
return m_pData[nIndex];
}
double& CMatrix::operator()(int nRow, int nCol)
{
assert(nRow * m_nCol + nCol < m_nRow* m_nCol);
return m_pData[nRow * m_nCol + nCol];
}
istream& operator>>(istream& is, CMatrix& m)
{
is >> m.m_nRow >> m.m_nCol;
m.Create(m.m_nRow, m.m_nCol,m.m_pData);
for (int i = 0; i < m.m_nRow * m.m_nCol; i++)
{
is >> m.m_pData[i];
}
return is;
}
ostream& operator<<(ostream& os, const CMatrix& m)
{
os << m.m_nRow << " " << m.m_nCol << endl;
double* pData = m.m_pData;
for (int i = 0; i < m.m_nRow; i++)
{
for (int j = 0; j < m.m_nCol; j++)
{
os << *pData++ << " ";
}
os << endl;
}
return os;
}
(5)数据类型转换,将创建的对象强制转换成double类
CMatrix::operator double()
{
double dS = 0;
for (int i = 0; i < m_nRow * m_nCol; i++)
{
dS += m_pData[i];
}
return dS;
}
3.主函数
#include <iostream>
#include <stdio.h>
#include "CMatrix.h"
using namespace std;
int main(int argc, char** argv)
{
double pData[10] = { 2,3,4,5 };
CMatrix m1,m2(2, 5, pData), m3("d:\\1.txt"), m4(m2);
cout << "输入矩阵行,列和对于数量的数值:" << endl;
cin >> m1;
m2.Set(1, 3, 10);
cout << "m1=" << m1 << "\nm2=" << m2 << "\nm3=" << m3 << "\nm4=" << m4;
m4 = m3;
m4[2] = m4 + 1;
if (m4 == m3)
{
cout << "Error !" << endl;
}
m4 += m3;
cout << "\nm4=" << m4 << endl;
cout << "sum of m4 = " << (double)m4 << endl;
return 0;
}
4.结果展示
5.总结
本次实验涉及到类的创建,删除,已经运算符的重载,对类的强制类型转换等等。还有析构函数的使用。本次实验编写明白很多项目构建的问题,其中对于内敛函数,无参函数让系统更快运行也有了深刻影响。对于各类重载方法有了大致的了解。