C++实验： 运算符重载

C++实验： 运算符重载

1.实验目的

（1）进一步了解运算符重载的概念与使用方法。

（2）掌握几种常用的运算符重载方法。

（3）了解转换构造函数的使用方法。

（4）了解在Visual C++6.0环境下进行运算符重载要注意的问题。

2.实验内容

（1）声明一个复数类，重载运算符函数作为其成员函数，使之用于复数计算；

（2）声明一个复数类，重载运算符“+”，使之用于复数加法运算，同时求复数、整数的和；

（3）求已知的矩阵之和，重载运算符“+”，使之用于矩阵相加；

（4）声明一个教师类和学生类，有部分数据成员相同，转换学生对象为教师类，将相同数据移植过去。

3.实验代码

#include 
using namespace std;

class Complex
{
public:
    Complex()
{ real = 0; imag = 0; }
    Complex(double r, double i) { real = r; imag = i; }
    Complex operator + (Complex &c2);
    Complex operator - (Complex &c2);
    Complex operator*(Complex &c2);
    Complex operator/(Complex &c2);
    void display();
private:
    double real;
    double imag;
};

Complex Complex::operator+(Complex &c2)
{
    Complex c;
    c.real= real + c2.real;
    c.imag= imag + c2.imag;
    return c;
}

Complex Complex::operator-(Complex &c2)
{
    Complex c;
    c.real= real - c2.real;
    c.imag= imag - c2.imag;
    return c;
}

Complex Complex::operator*(Complex &c2)
{
    Complex c;
    c.real= real * c2.real -imag * c2.imag;
    c.imag= imag * c2.real +real * c2.imag;
    return c;
}

Complex Complex::operator/(Complex &c2)
{
    Complex c;
    c.real= (real*c2.real +imag * c2.imag) /(c2.real*c2.real + c2.imag*c2.imag);
    c.imag= (imag*c2.real -real * c2.imag) /(c2.real*c2.real + c2.imag*c2.imag);
    return c;
}

void Complex::display()
{
    cout<< "(" << real << "," << imag << "i)" << endl;
}
int main()
{
    Complex c1(3, 4), c2(5,-10), c3;
    c3= c1 + c2;
    cout<< "c1+c2=";
    c3.display();
    c3= c1 - c2;
    cout<< "c1-c2=";
    c3.display();
    c3= c1 * c2;
    cout<< "c1*c2=";
    c3.display();
    c3= c1 / c2;
    cout<< "c1/c2=";
    c3.display();
    return 0;
}

#include 
using namespace std;

class Complex
{
public:
    Complex()
{ real = 0; imag = 0; }
    Complex(double r, double i) { real = r, imag = i; }
    Complex operator + (Complex &c2);
    Complex operator + (int &i);
    friend Complex operator + (int &, Complex &);
    void display();
private:
    double real;
    double imag;
};

Complex Complex::operator + (Complex &c)
{
    return Complex(real + c.real, imag + c.imag);
}

Complex Complex::operator + (int &i)
{
    return Complex(real + i, imag);
}

void Complex::display()
{
    cout<< "(" << real << "," << imag << "i)" << endl;
}

Complex operator + (int &i, Complex &c)
{
    return Complex(i + c.real, c.imag);
}

int main()
{
    Complex c1(3, 4), c2(5,-10), c3;
    int i = 5;
    c3= c1 + c2;
    cout<< "c1 + c2 = ";
    c3.display();
    c3= i + c1;
    cout<< "i + c1 = ";
    c3.display();
    c3= c1 + i;
    cout<< "c1 + i = ";
    c3.display();
    return 0;
}

#include 
using namespace std;

class Matrix
{
public:
    Matrix();
    friend Matrix operator + (Matrix &, Matrix &);
    void input();
    void display();
private:
    int mat[2][3];
};

Matrix::Matrix()
{
    for (int i = 0; i < 2;i++)
         for (int j = 0; j < 3;j++)
             mat[i][j]= 0;
}

Matrix operator + (Matrix &a, Matrix &b)
{
    Matrix c;
    for (int i = 0; i < 2;i++)
         for (int j = 0; j < 3;j++)
         {
             c.mat[i][j]= a.mat[i][j] + b.mat[i][j];
         }
    return c;
}

void Matrix::input()
{
    cout<< "input value of matrix :" << endl;
    for (int i = 0; i < 2;i++)
         for (int j = 0; j < 3;j++)
             cin>> mat[i][j];
}

void Matrix::display()
{
    for (int i = 0; i < 2;i++)
    {
         for (int j = 0; j < 3;j++)
         {
             cout<< mat[i][j] << " ";
         }
         cout<< endl;
    }
}

int main()
{
    Matrix a, b, c;
    a.input();
    b.input();
    cout<< endl << "Matrix a : " << endl;
    a.display();
    cout<< endl << "Matrix b : " << endl;
    b.display();
    c= a + b;
    cout<< endl << "Matrix c = Matrix a + Matrix b : " << endl;
    c.display();
    return 0;
}

#include 
using namespace std;

class Student
{
public:
    Student(int,char[], char, float);
    int get_num() { return num; }
    char * get_name() { return name; }
    char get_sex() { return sex; }
    void display()
    {
         cout<< "num:"<< num << "\nnmae : " <<name << "\nsex : " << sex << "\nscore : "<< score << "\n\n";
    }
private:
    int num;
    char name[20];
    char sex;
    float score;
};

Student::Student(int n, char nam[], char s, float sco)
{
    num = n;
    strcpy(name,nam);
    sex = s;
    score = sco;
}

class Teacher
{
public:
    Teacher() {}
    Teacher(Student&);
    Teacher(int n, char nam[], char sex, float pay);
    void display();
private:
    int num;
    char name[20];
    char sex;
    float pay;
};

Teacher::Teacher(int n, char nam[], char s, float p)
{
    num = n;
    strcpy(name,nam);
    sex = s;
    pay = p;
}

Teacher::Teacher(Student& stud)
{
    num =stud.get_num();
    strcpy(name,stud.get_name());
    sex =stud.get_sex();
    pay = 1500;
}

void Teacher::display()
{
    cout<< "num:"<< num << "\nname : " <<name << "\nsex" << sex << "\npay:"<< pay << "\n\n";
}

int main()
{
    Teacher
teacher1(10001, "Li", 'f', 1234.5), teacher2;
    Student
student1(20010, "Wang", 'm', 89.5);
    cout<< "student1:" << endl;
    student1.display();
    teacher2 =
Teacher(student1);
    cout<< "teacher2:" << endl;
    teacher2.display();
    return 0;
}

4.实验结果

（1）

（2）

（3）

（4）

5.实验总结

（1）运算符重载的方法是定义一个重载运算符函数的重载，使指定的运算符不仅能实现原有的功能，而且能实现在函数中指定的新功能；

（2）运算符重载实质上是函数的重载。