C++ 开发之实现操作符重载的实例

C++操作符重载

实现效果图：

实例代码：

Matrix.h

#pragma once
#include "vector"
#include "iostream"
#define rep(i,n) for(int i=1;i<=n;i++) //宏定义for循环，精简代码
using namespace std;
class Matrix
{
public:
  //基本构造函数
  Matrix(int Row=0, int Column=0);
  //拷贝构造函数或者复制构造函数
  Matrix(const Matrix& matrix);
  //赋值操作符重载，必须为成员函数，不然会报错
  Matrix& operator=(const Matrix& matrix);
  //复合赋值操作符重载，建议重载为成员函数
  Matrix& operator+=(const Matrix& matrix);
  Matrix& operator*=(const Matrix& matrix);
  Matrix& operator*=(const float& number);
  Matrix& operator*=(const int& number);
  Matrix& operator-=(const Matrix& matrix);
  Matrix& operator/=(const float& number);
  float& operator[](const size_t& index);
  Matrix& operator++();//前缀式自增
  Matrix& operator--();//前缀式自减
  Matrix operator++(int); //后缀式自增
  Matrix operator--(int); //后缀式自减
  //算术和关系操作符一般为非成员函数，声明为友元
  friend Matrix operator+(const Matrix& matrix1, const Matrix& matrix2);
  friend Matrix operator-(const Matrix& matrix1, const Matrix& matrix2);
  friend Matrix operator*(const Matrix& matrix1, const Matrix& matrix2);
  friend Matrix operator*(const Matrix& matrix1, const float& number);
  friend Matrix operator*(const Matrix& matrix1, const int& number);
  friend bool operator==(const Matrix& matrix1, const Matrix& matrix2);
  friend bool operator!=(const Matrix& matrix1, const Matrix& matrix2);
  //输出操作符<<的重载,必须声明为友元
  friend ostream& operator<<(ostream& os, const Matrix&object);
  //输入操作符>>重载，必须声明为友元
  friend istream& operator >>(istream& in,Matrix&object);
  void Display();
  ~Matrix();
public:
  int Row;
  int Column;
  vector<vector<float> > data; //二维vector，用于存放矩阵类数据
};

Matrix.cpp

#include "stdafx.h"
#include "Matrix.h"
#include "iomanip"
//构造函数
Matrix::Matrix(int Row/* =0 */, int Column/* =0 */){
  this->Row = Row;
  this->Column = Column;
  data.resize(Row + 1); //申请行数为row+1，0号位不用
  rep(i, Row)
    data[i].resize(Column + 1); //申请各行的列数
  rep(i, Row)
    rep(j, Column)
    data[i][j] = 0; //每个元素初始化为0，方便后面计算
}
//打印函数
void Matrix::Display(){
  rep(i, Row)
  {
    rep(j, Column)
      cout << setw(8) << data[i][j] << ' ';
    cout <<endl;
  }
}
//拷贝构造函数
Matrix::Matrix(const Matrix& matrix){
  Row = matrix.Row;
  Column = matrix.Column;
  data.resize(Row+1); //申请行数为row，0号位不用
  rep(i, Row)
    data[i].resize(Column+1); //申请各行的列数
  rep(i, Row)
    rep(j, Column)
    data[i][j] = matrix.data[i][j];
}
//赋值操作符重载
Matrix& Matrix::operator=(const Matrix& matrix){
  if (this==&matrix)
  {
    return *this;
  }
  Row = matrix.Row;
  Column = matrix.Column;
  //分配资源
  data.resize(Row + 1); //申请行数为row+1，0号位不用
  rep(i, Row)
    data[i].resize(Column + 1); //申请各行的列数
  rep(i, Row)
    rep(j, Column)
    data[i][j] = matrix.data[i][j];
  //返回本对象的引用
  return *this;
}
//复合赋值操作符重载
Matrix& Matrix::operator+=(const Matrix& matrix){
  if (Row == matrix.Row&&Column == matrix.Column)
  {
    rep(i, Row)
    {
      rep(j,Column)
      {
        data[i][j] += matrix.data[i][j];
      }
    }
  }
  return *this;
}
Matrix& Matrix::operator-=(const Matrix& matrix){
  if (Row == matrix.Row&&Column == matrix.Column)
  {
    rep(i, Row)
    {
      rep(j, Column)
      {
        data[i][j] -= matrix.data[i][j];
      }
    }
  }
  return *this;
}
Matrix& Matrix::operator*=(const float& number){
  rep(i, Row)
  {
    rep(j, Column)
    {
      data[i][j] = data[i][j] * number;
    }
  }
  return *this;
}
Matrix& Matrix::operator*=(const int& number){
  rep(i, Row)
  {
    rep(j, Column)
    {
      data[i][j] = data[i][j] * number;
    }
  }
  return *this;
}
Matrix& Matrix::operator*=(const Matrix& matrix){
  //先保存矩阵的值
  Matrix temp(Row, Column);
  rep(i, temp.Row)
  {
    rep(j, temp.Column)
    {
      temp.data[i][j] = data[i][j];
    }
  }
  //改变矩阵的大小和值
  Column = matrix.Column;
  data.clear();    //清除数据
  data.resize(Row+1); //申请行数为row+1，0号位不用
  rep(i, Row)
    data[i].resize(Column+1); //申请各行的列数
  //重新给矩阵赋值
  rep(i, temp.Row)
  {
    rep(j, matrix.Column)
    {
      double sum = 0;
      rep(k, temp.Column)
        sum += temp.data[i][k] * matrix.data[k][j];
      data[i][j] = sum; //改变矩阵的值
    }
  }
  return *this;
}
Matrix& Matrix::operator/=(const float& number){
  rep(i, Row)
  {
    rep(j, Column)
    {
      data[i][j] = data[i][j] / number;
    }
  }
  return *this;
}
//前缀式自增
Matrix& Matrix::operator++(){
  //对每个元素都加1
  rep(i, Row)
  {
    rep(j, Column)
    {
      data[i][j] +=1;
    }
  }
  return *this;
}
//前缀式自减
Matrix& Matrix::operator--(){
  //对每个元素都减1
  rep(i, Row)
  {
    rep(j, Column)
    {
      data[i][j] -= 1;
    }
  }
  return *this;
}
//后缀式自增
Matrix Matrix::operator++(int){
  //拷贝构造函数
  Matrix ret(*this);
  //对每个元素都加1
  rep(i, Row)
  {
    rep(j, Column)
    {
      data[i][j] += 1;
    }
  }
  return ret;
}
//后缀式自减
Matrix Matrix::operator--(int){
  //拷贝构造函数
  Matrix ret(*this);
  //对每个元素都减1
  rep(i, Row)
  {
    rep(j, Column)
    {
      data[i][j] -= 1;
    }
  }
  return ret;
}
//析构函数
Matrix::~Matrix()
{
  data.clear();
}
//加法操作符重载
Matrix operator+(const Matrix& matrix1, const Matrix& matrix2){
  Matrix temp(matrix1.Row, matrix1.Column);
  if (matrix1.Row == matrix2.Row&&matrix1.Column == matrix2.Column)
  {
    rep(i, matrix1.Row)
    {
      rep(j, matrix2.Column)
      {
        temp.data[i][j] = matrix1.data[i][j]+matrix2.data[i][j];
      }
    }
  }
  return temp;
}
//减法操作符重载
Matrix operator-(const Matrix& matrix1, const Matrix& matrix2){
  Matrix temp(matrix1.Row, matrix1.Column);
  if (matrix1.Row == matrix2.Row&&matrix1.Column == matrix2.Column)
  {
    rep(i, matrix1.Row)
    {
      rep(j, matrix2.Column)
      {
        temp.data[i][j] = matrix1.data[i][j] - matrix2.data[i][j];
      }
    }
  }
  return temp;
}
//乘法操作符重载
Matrix operator*(const Matrix& matrix1, const Matrix& matrix2){
  Matrix temp(matrix1.Row, matrix2.Column);
  rep(i, temp.Row)
  {
    rep(j, temp.Column)
    {
      double sum = 0;
      rep(k, matrix1.Column)
        sum += matrix1.data[i][k] * matrix2.data[k][j];
      temp.data[i][j] = sum;
    }
  }
  return temp;
}
//乘法操作符重载
Matrix operator*(const Matrix& matrix1, const float& number){
  Matrix temp(matrix1.Row, matrix1.Column);
  rep(i, temp.Row)
  {
    rep(j, temp.Column)
    {
      temp.data[i][j] = matrix1.data[i][j]* number;
    }
  }
  return temp;
}
//乘法操作符重载
Matrix operator*(const Matrix& matrix1, const int& number){
  Matrix temp(matrix1.Row, matrix1.Column);
  rep(i, temp.Row)
  {
    rep(j, temp.Column)
    {
      temp.data[i][j] = matrix1.data[i][j] * number;
    }
  }
  return temp;
}
//等于关系操作符重载
bool operator==(const Matrix& matrix1, const Matrix& matrix2){
  //只有维数相等才有可比性
  if (matrix1.Row==matrix2.Row&&matrix1.Column==matrix2.Column)
  {
    rep(i, matrix1.Row)
    {
      rep(j, matrix1.Column)
      {
        if (matrix1.data[i][j]!=matrix2.data[i][j])
        {
          return false;
        }
      }
    }
    return true;
  }
  else
  {
    return false;
  }
}
//不等于关系操作符重载
bool operator!=(const Matrix& matrix1, const Matrix& matrix2){
  //只有维数相等才有可比性
  if (matrix1.Row == matrix2.Row&&matrix1.Column == matrix2.Column)
  {
    rep(i, matrix1.Row)
    {
      rep(j, matrix1.Column)
      {
        if (matrix1.data[i][j] != matrix2.data[i][j])
        {
          return true;
        }
      }
    }
    return false;
  }
  else
  {
    return false;
  }
}
//输出操作符重载
ostream& operator<<(ostream& os, const Matrix&object){ 

  rep(i, object.Row)
  {
    rep(j, object.Column)
      os << setw(8) << object.data[i][j] << ' ';
    os <<endl;
  }
  return os;
}
//输入操作符重载
istream& operator >>(istream& in, Matrix&object){
  rep(i, object.Row)
    rep(j, object.Column)
    in >> object.data[i][j];
  return in;
}

main.c

#include "iostream"
#include "Matrix.h"
using namespace std;
int main(){
  int row1, row2, col1, col2;
  cout << "请输入第一个矩阵的行和列:\n";
  cin >> row1 >> col1;
  Matrix m1(row1, col1);
  cout << "请输入" << row1 << '*' << col1 << "个数:\n";
  cin >> m1;
  cout << "输出矩阵的值:\n";
  cout << m1;
  cout << "请输入第二个矩阵的行和列:\n";
  cin >> row2 >> col2;
  Matrix m2(row2, col2);
  cout << "请输入" << row2 << '*' << col2 << "个数:\n ";
  cin >> m2;
  cout << "输出矩阵的值:\n";
  cout << m2;
  if (col1 != row2)
    cout << "这两个矩阵无法相乘\n";
  else
  {
    cout << "判断矩阵m1与m2是否相等：\n";
    if (m1==m2)
    {
      cout << "m1和m2相等：\n";
    }
    else
    {
      cout << "m1和m2不相等：\n";
    } 

    cout << "m1拷贝构造m3矩阵结果输出：\n";
    Matrix m3(m1);
    cout << m3; 

    cout << "m1赋值重载m4矩阵结果输出：\n";
    Matrix m4(m1.Row,m1.Column);
    m4 = m1;
    cout << m4; 

    cout << "m1*m2矩阵相乘输出m5：\n";
    Matrix m5(m1.Row, m2.Column);
    m5 = m1*m2;
    cout << m5; 

    cout << "矩阵m1*2输出m6：\n";
    Matrix m6(m1.Row, m1.Column);
    m6 = m1*2;
    cout << m6; 

    cout << "矩阵m1*0.5输出m7：\n";
    Matrix m7(m1.Row, m1.Column);
    m7 = m1 * 0.5;
    cout << m7; 

    cout << "m1*m2矩阵相乘输出m1：\n";
    m1 *= m2;
    cout << m1; 

    cout << "m1矩阵前自增输出\n";
    cout << ++m1; 

    cout << "m1矩阵后自增输出\n";
    cout << m1++; 

    cout << "m1矩阵输出\n";
    cout << m1; 

    cout << "m1矩阵前自减输出\n";
    cout << --m1; 

    cout << "m1矩阵后自减输出\n";
    cout << m1--; 

    cout << "m1矩阵输出\n";
    cout << m1;
  }
  return 0;
}

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