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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