实验1 类与对象

实验任务三

Complex.hpp

 1 #include<iostream>
 2 #include<cmath>
 3 using namespace std;
 4 class Complex{
 5     private:
 6         double real, imag;
 7     public:
 8         Complex(double r = 0, double i = 0):real(r), imag(i){}
 9         Complex(const Complex & c){real = c.real; imag = c.imag;}
10         double get_real()const{return real;}
11         double get_imag()const{return imag;}
12         void show()const;
13         void add(const Complex &c);
14         friend Complex add(const Complex &c1, const Complex &c2);
15         friend bool is_equal(const Complex &c1, const Complex &c2);
16         friend double abs(const Complex &c);
17 }; 
18 
19 void Complex::show()const{
20     if(imag > 0)
21         cout << real << " + " <<imag << "i";
22     else if(imag < 0)
23         cout << real <<" - " << -1*imag << "i";
24     else
25         cout << real;
26 }
27 void Complex::add(const Complex &c){
28     real += c.real;
29     imag += c.imag;
30 }
31 Complex add(const Complex &c1, const Complex &c2){
32     Complex c;
33     c.real = c1.real + c2.real;
34     c.imag = c1.imag + c2.imag;
35     return c;
36 } 
37 bool is_equal(const Complex &c1, const Complex &c2){
38     if(c1.real==c2.real && c1.imag==c2.imag)
39         return true;
40     return false;
41 }
42 double abs(const Complex &c){
43     double s = sqrt(c.real * c.real + c.imag * c.imag);
44     return s;
45 }

task3.cpp

#include "Complex.hpp"
#include <iostream>

int main()
{
    using namespace std;

    Complex c1(-9, 2);
    const Complex c2(6.3);
    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;
}

实验结果

实验任务4

User.hpp

 1 #include<iostream>
 2 #include<cstring> 
 3 using namespace std;
 4 
 5 class User{
 6     private:
 7         string name;
 8         string passwd;
 9         string email;
10         static int n;
11     public:
12         User(string name0, string passwd0 = "111111", string email0 = ""):
13             name(name0), passwd(passwd0), email(email0){ ++n;}
14         void set_email();
15         void change_passwd();
16         void print_info()const;
17         static void print_n();
18 };
19 int User::n = 0;
20 
21 void User::set_email(){
22     cout << "Enter email address:";
23     cin >> email;
24     cout << "email is set successfully..." << endl;
25 }
26 
27 void User::change_passwd(){
28     string p;
29     cout << "Enter old password: ";
30     for(int i=0; i<3; i++){
31         cin >> p;
32         if(p==passwd){
33             cout << "Enter new password: ";
34             cin >> passwd;
35             cout << "new password is set successfully..." << endl;
36             break;
37         }
38         else{
39             cout << "password input error.";
40             if(i==0||i==1)
41                 cout << " Please re-enter again: ";
42             else
43                 cout << "Please try after a while." << endl;
44         }
45     }    
46 }
47 
48 void User::print_info()const{
49     cout << "name: " << name << endl;
50     cout << "password: ******" << endl;
51     cout << "email: " << email << endl;
52     
53 }
54 
55 void User::print_n(){
56     if(n == 1)
57         cout << "there is " << n << " user." << endl;
58     else
59         cout << "there are " << n << " users." << endl;
60 }

task4.cpp

 1 #include "User.hpp"
 2 #include <iostream>
 3 
 4 int main()
 5 {
 6     using namespace std;
 7 
 8     cout << "testing 1......" << endl;
 9     User user1("Jonny", "92197", "xyz@hotmail.com");
10     user1.print_info();
11 
12     cout << endl
13          << "testing 2......" << endl
14          << endl;
15     User user2("Leonard");
16     user2.change_passwd();
17     user2.set_email();
18     user2.print_info();
19 
20     User::print_n();
21 }

实验结果