实验二 类与对象2

4. 实验任务4
不使用C++标准库，自行设计并实现一个简化版复数类Complex

Complex.hpp

 1 #include <iostream>
 2 #include <math.h> 
 3 using namespace std; 
 4 
 5 class Complex {
 6     
 7 public:
 8     Complex(double r = 0, double i = 0): real{r}, imag{i} {}
 9     Complex(const Complex& obj): real{obj.real}, imag{obj.imag} {}
10     
11     double get_real() const {
12         return real;
13     }
14     double get_imag() const {
15         return imag;
16     }
17     void show() const;
18     void add(const Complex& c);
19     
20     friend Complex add(Complex c1, Complex c2);
21     friend bool is_equal(Complex c1, Complex c2);
22     friend int abs(Complex c1);
23     
24 private:
25     double real, imag;
26 };
27 
28 void Complex::show() const {
29     if(imag == 0) {
30         cout << real;
31     }
32     else if(imag < 0) {
33         cout << real << " - " << -1 * imag << "i";
34     } else{
35         cout << real << " + " << imag << "i";
36     }
37 }
38 void Complex::add(const Complex& c) {
39     real += c.real;
40     imag += c.imag;
41 }
42 
43 Complex add(Complex c1, Complex c2) {
44     Complex c3(c1.real + c2.real, c1.imag + c2.imag);
45     return c3;
46 }
47 bool is_equal(Complex c1, Complex c2) {
48     return (c1.real == c2.real && c2.imag == c1.imag);
49 }
50 int abs(Complex c) {
51     return sqrt(c.real * c.real + c.imag * c.imag);
52 }

task4.cpp

 1 #include "Complex.hpp"
 2 #include <iostream>
 3 #include <math.h> 
 4 // 类测试 
 5 void test() {
 6     using namespace std;
 7 
 8     Complex c1(3, -5);
 9     const Complex c2(3.5);
10     Complex c3(c1);
11 
12     cout << "c1 = ";
13     c1.show();
14     cout << endl;
15 
16     cout << "c2 = ";
17     c2.show();
18     cout << endl;
19     cout << "c2.imag = " << c2.get_imag() << endl;
20 
21     cout << "c3 = ";
22     c3.show();
23     cout << endl;
24 
25     cout << "abs(c1) = ";
26     cout << abs(c1) << endl;
27 
28     cout << boolalpha;
29     cout << "c1 == c3 : " << is_equal(c1, c3) << endl;
30     cout << "c1 == c2 : " << is_equal(c1, c2) << endl;
31 
32     Complex c4;
33     c4 = add(c1, c2);
34     cout << "c4 = c1 + c2 = ";
35     c4.show();
36     cout << endl;
37 
38     c1.add(c2);
39     cout << "c1 += c2, " << "c1 = ";
40     c1.show();
41     cout << endl;
42 }
43 
44 int main() {
45     test();
46 }

5. 实验任务5

User.hpp

 1 #include <iostream>
 2 #include <string>
 3 
 4 using namespace std;
 5 
 6 class User {
 7 
 8 public:
 9     User(string n, string p = "111111", string e = "") : 
10         name{ n }, passwd{ p }, email{ e } { 
11             num ++; 
12         }
13 
14     void set_email();
15     void change_passwd();
16     void print_info();
17     static void print_n() {
18         cout << "there are " << num << " users."; 
19     }
20 
21 private: 
22     string name, passwd, email;
23     static int num;
24 };
25 
26 int User::num = 0;
27 
28 void User::set_email() {
29     cout << "Enter email address: " ;
30     string email_;
31     cin >> email_;
32     email = email_;
33     cout << "email is set successfully..." << endl;
34 }
35 
36 void User::change_passwd() {
37     string old_pwd, new_pwd;
38     int count = 1;
39 
40     cout << "Enter old password: ";
41     cin >> old_pwd;
42     
43     while(old_pwd != passwd) {
44         cout << "password input error. Please re-enter again: ";
45         cin >> old_pwd;
46         count++;
47         
48         if(count == 3) {
49             cout << "password input error. Please try after a while. " << endl;
50             return;
51         }
52     }
53     cout << "Enter new password: ";
54     cin >> new_pwd; 
55     passwd = new_pwd;
56     
57     cout << "new passwd is set successfully..." << endl;
58     
59 }
60 
61 void User::print_info() {
62     string pwd(passwd.length(), '*');
63     cout << "name:\t" << name << endl;
64     cout << "passwd:\t" << pwd << endl;
65     cout << "email:\t" << email << endl;    
66 }

task5.cpp

 1 #include "User.hpp"
 2 #include <iostream>
 3 #include <string>
 4 
 5 // 测试User类 
 6 void test() {
 7     using std::cout;
 8     using std::endl;
 9     using std::string;
10     
11     cout << "testing 1......\n";
12     User user1("Jonny", "92197", "[email protected]");
13     user1.print_info();
14 
15     cout << endl
16          << "testing 2......\n\n";
17          
18     User user2("Leonard");
19     user2.change_passwd();
20     user2.set_email();
21     user2.print_info();
22 
23     cout << endl;
24     User::print_n();
25 }
26 
27 int main() {
28     test();
29 }

实验总结 ：

hpp文件中 ，不能忘了导入需要的头文件， using 所需要的命名空间中的成员