实验一 类与对象

 

实验结论：

实验任务三：

Complex.hpp

#include<iostream>
#include<math.h>
using namespace std;


class Complex
{
public:
    Complex():real(0),imag(0){}
    Complex(float x) :real(x),imag(0){}
    Complex(float x,float y):real(x),imag(y){}
    float get_real()const{return real;}
    float get_imag()const{return imag;}
    void show()const{
        if(imag==0)cout<<real<<endl;
        if(imag>0)cout<<real<<"+"<<imag<<"I"<<endl;
    if(imag<0) cout<<real<<imag<<"i"<<endl;}
    void add(Complex p){real+=p.real;imag+=p.imag;}
     friend Complex add(Complex a,Complex b){
        Complex c;
        c.real=a.real+b.real;
        c.imag=a.imag+b.imag;
        return c;
    }
     friend bool is_equal(Complex a,Complex b){if(a.real==b.real&&a.imag==b.imag) return true;
     if(a.real!=b.real||a.imag!=b.imag) return false;}
     friend float abs(Complex &a){
     float x;
     x=sqrt(a.real*a.real+a.imag*a.imag);
     return x;



     }
private:
    float real;
    float imag;



};

task3.cpp

#include<math.h>
#include <iostream>
#include"Complex.hpp"
using namespace std;



int main()
{
    using namespace std;

    Complex c1(3, -4);
    const Complex c2(4.5);
    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;
}

运行截图：

 更换数据后的截图：

 

 

 

实验任务四：

User.hpp:

#include<iostream>
#include<string>
using namespace std;

class User{
public:
    User(string a,string b="111111",string c=" "):name(a){passwd=b;email=c;n++;}
    void set_email(){char a;
    cout<<"Enter email address:";
    cin>>a;
    email=a;
    cout<<email<<endl;
    cout<<"email is set successfully..."<<endl;
    }
    void change_passwd(){
        string a;
        int n=3;
        cout<<"Enter old password:";

        while(1){
        cin>>a;
        if(a!=passwd){cout<<"password input error.Please re-enter again:";n--;}
        
        if(n==0){cout<<"password input error.Please try after a while."<<endl;break;}
        if(a==passwd){
            cout<<"Enter new passward:";
            cin>>a;
            passwd=a;
            
            
            break;}        
        }
    }
    void print_info()
    {
        cout<<"name:"<<name<<endl;
        cout<<"passwd:"<<"******"<<endl;
        cout<<"email:"<<email<<endl;

    
    
    
    }
    static void print_n()
    {
        cout<<"there are "<<n<<" users"<<endl;
    
    
    }
    
    
    

private:
    static int n;
    string name;
    string email;
    string passwd;

};
 int User::n=0;

 

task4.cpp:

#include"User.hpp"
#include<string>
#include <iostream>
using namespace std;



int main()
{
    using namespace std;

    cout << "testing 1......" << endl;
    User user1("Jonny", "92197", "xyz@hotmail.com");
    user1.print_info();

    cout << endl
         << "testing 2......" << endl
         << endl;
    User user2("Leonard");
    user2.change_passwd();
    user2.set_email();
    user2.print_info();

    User::print_n();
}

运行截图：

 输入密码没有错误的运行截图：

 

 

 更换数据后的运行截图：