实验一 类与对象

实验任务三
#include<iostream>
#include<math.h>
using namespace std;
class Complex {
public:
    Complex(double x = 0, double y = 0) :real(x), imag(y) {};
    Complex(Complex const& c) :real(c.real), imag(c.imag) {};
    double get_real() const { return real; };
    double get_imag() const { return imag; };
    void show()const;
    void add(Complex const &c1) {
        Complex c;
        c.real = real + c1.real;
        c.imag = imag + c1.imag;
        real = c.real;
        imag = c.imag;
    };
    friend Complex add(Complex c1, Complex c2);
    friend bool is_equal(Complex const c1, Complex const c2);
    friend double abs(Complex c);
private:
    double real;
    double imag;
};
void Complex::show()const {
    {
        if (imag == 0)
            cout << real;
        else if (imag >= 0)
            cout << real << "+" << imag << 'i';
        else
            cout << real << imag << "i";
    };
}
Complex add(Complex c1, Complex c2) {
    Complex c3;
    c3.real = c1.real + c2.real;
    c3.imag = c1.imag + c2.imag;
    return c3;
};
bool is_equal(Complex const c1, Complex const c2) {
    if (c1.real == c2.real && c1.imag == c2.imag)
        return true;
    else return false;
};
double abs(Complex c) {
    return sqrt(c.real * c.real + c.imag * c.imag);
};

 

 

实验任务四
#include<iostream>
#include<string>
using namespace std;
class User
{
    public:
        User(string name1);
        User(string name1,string password1,string email1);
         
        void set_email();   
        void change_passwd();  
        void print_info();    
        static void print_n();
         
    private:
        string name,password,email;
        static int n;  
};


int User::n=0;  


User::User(string name1)
{
    name=name1;
    password="111111";
    email="";
    n++;
}

User::User(string name1,string password1,string email1)
{
    name=name1;
    password=password1;
    email=email1;
    n++;
}


void User::set_email()
{
    string t;
    cout<<"Enter email address:";
    cin>>t;
    email=t;
    cout<<"email is set successfully···"<<endl;
}

void User::change_passwd()
{
    string t0,t1; 
    cout<<"Enter old password:";
    for(int i=1;i<=3;i++)
    {
        cin>>t0;
        if(t0==password)
        {
            cout<<"Enter new password:";
            cin>>t1;
            password=t1;
            break;
        }
        else if(i<=2)
        {
            cout<<"password input error. Please re-enter again:";
        }
        else cout<<"password input error. Please try after a while."<<endl;  
    }
}

void User::print_info()
{
    cout<<"name:"<<name<<endl;
    cout<<"passwd:"<<"******"<<endl;
    cout<<"email:"<<email<<endl;
}
void User::print_n()
{
    if(n==1)
      cout<<"there are "<<n<<" user."<<endl;
    else cout<<"there are "<<n<<" users."<<endl;
}