实验一 类与对象

#include<iostream>
#include<cmath>
using namespace std;
class Complex{
    private:
        double real, imag;

    public:
        Complex();
        Complex(double r = 0, double i = 0);
        Complex(double r);
        Complex(const Complex &c);
        
        double get_real() const
        double get_imag() const
        void show() const;
        void add(const Complex &c);
        friend Complex add(const Complex &c1, const Complex &c2);
        friend bool is_equal(const Complex &c1, const Complex &c2);
        friend double abs(const Complex &c);
};

void Complex::show() const
{
    double n1,n2;
    n1=get_real();
    //cout<<n1<<endl;
    n2=get_imag();
    if(n1==0&&n2==0)
    {
        cout<<n1;
    }
    else {
        if(n1==0)
        {
            cout<<n2<<"i";
        }
        else {
            if(n2==0)
            {
                cout<<n1;
            }
            else {
                if(n2>0)
                 cout<<n1<<"+"<<n2<<"i";
                else cout<<n1<<n2<<"i";
                    }
                }
            }
}

void Complex::add(const Complex &c){
    real += c.real;
    imag += c.imag;
}

Complex add(const Complex &c1, const Complex &c2){
    Complex c3;
    c3.real = c1.real + c2.real;
    c3.imag = c1.imag + c2.imag;
    return c;
}

bool is_equal(const Complex &c1, const Complex &c2){
    if(c1.real==c2.real && c1.imag==c2.imag)
        return true;
    return false;
}

double abs(const Complex &c){
    double s = sqrt(c.real * c.real + c.imag * c.imag);
    return s;
}

task 3:

#include "Complex.hpp"
#include <iostream>
int main()
{
    using namespace std;

    Complex c1(8, -9);
    const Complex c2(6.5);
    Complex c3(c1);

    cout << "c1 = ";
    c1.show();
    cout << endl;

    cout << "c2 = ";
    c2.show();
    cout << endl;
    cout << "c2.imag = " << c2.get_imag() << endl;

    cout << "c3 = ";
    c3.show();
    cout << endl;

    cout << "abs(c1) = ";
    cout << abs(c1) << endl;

    cout << boolalpha;
    cout << "c1 == c3 : " << is_equal(c1, c3) << endl;
    cout << "c1 == c2 : " << is_equal(c1, c2) << endl;

    Complex c4;
    c4 = add(c1, c2);
    cout << "c4 = c1 + c2 = ";
    c4.show();
    cout << endl;

    c1.add(c2);
    cout << "c1 += c2, " << "c1 = ";
    c1.show();
    cout << endl;
}

输出结果：

 

 

 

实验任务 4：

User.hpp:

#include<iostream>
#include<string>
using namespace std;
class User
{
    private:
        string name,password,email;
        static int n; 

    public:
        User(string n1);
        User(string n1,string p1,string e1);
         
        void set_email();   
        void change_passwd();  
        void print_info();    
        static void print_n();
};


int User::n=0;  


User::User(string n1)
{
    n++;
    name=n1;
    password="111111";
    email="";
}

User::User(string n1,string p1,string e1)
{
    n++;
    name=n1;
    password=p1;
    email=e1;
}


void User::set_email()
{
    string ad;
    cout<<"Enter email address:";
    cin>>ad;
    email=ad;
    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;
}