实验2 类和对象（2）

标签：std const cout 对象 void Complex 实验 using

实验任务4

 1 #pragma once
 2 
 3 #include<iostream>
 4 #include<cmath>
 5 
 6 using std::cout;
 7 using std::endl;
 8 
 9 class Complex{
10     public:
11         //构造函数 
12         Complex(float r = 0.0, float i = 0.0): real{r}, imag{i} {}
13         Complex(const Complex &obj): real{obj.real}, imag{obj.imag} {}
14     
15     public:
16         //普通成员函数
17         float get_real() const { return real; }
18         float get_imag() const { return imag; } 
19         void show() const;
20         void add(const Complex &obj); 
21         
22         //友源函数
23         friend Complex add(const Complex &c1, const Complex &c2) ;
24         friend bool is_equal(const Complex &c1, const Complex &c2);
25         friend double abs(const Complex &obj); 
26         
27     private:
28         float real; // 复数的实部
29         float imag; // 复数的虚部 
30 };
31  
32 void Complex::show() const {
33     if(imag > 0){
34         cout << real << " + " << imag << "i";
35     }
36     else if(imag < 0){
37         cout << real << " - " << abs(imag) << "i";
38     }
39     else{
40         cout << real ;  
41     } 
42      
43 }
44 
45 void Complex::add(const Complex &obj) {
46     real += obj.real;
47     imag += obj.imag;
48 }
49 
50 Complex add(const Complex &c1, const Complex &c2) { 
51    return Complex(c1.real+c2.real, c1.imag+c2.imag); 
52 }
53 
54 bool is_equal(const Complex &c1, const Complex &c2) {
55     if(c1.real == c2.real && c1.imag == c2.imag) return true;
56     return false;
57 }
58 
59 double abs(const Complex &obj) {
60     return sqrt(obj.real * obj.real + obj.imag * obj.imag);
61 }

Complex.hpp

 1 #include "Complex.hpp"
 2 #include <iostream>
 3 
 4 // 类测试
 5 void test() {
 6     using namespace std;
 7 
 8     Complex c1(3, -4);
 9     const Complex c2(4.5);
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 }

task4.cpp

测试结果截图：

 

 

 

 

实验任务5

 1 #pragma once
 2 
 3 #include<iostream>
 4 #include<string> 
 5 
 6 using std::cout;
 7 using std::cin;
 8 using std::endl;
 9 using std::string;
10 
11 class User{
12     public:
13         User(string n, string p = "111111", string e = "");
14         void set_email() ;
15         void change_passwd();
16         void print_info();
17         static void print_n() { cout << "there are " << count << " users" <<endl; }
18     
19     public:
20         static int count;
21         
22     private:
23         string name;
24         string passwd;
25         string email;
26 };
27 
28 int User::count = 0;
29 
30 User::User(string n, string p /*= "111111"*/, string e /*= "111111"*/){
31     name = n;
32     passwd = p;
33     email = e;
34     count++;
35 }
36 
37 void User::set_email() {
38     string s1;
39     cout << "Enter email address: ";
40     cin >> s1; 
41     email = s1;
42     cout << "email is set successfully..." << endl;
43 }
44 
45 void User::change_passwd() {
46     cout << "Enter old password: ";
47     int times = 0;
48     while(times < 3){
49         string s1;
50         cin >> s1;
51         if(s1 == passwd){
52             cout << "Enter new passwd: ";
53             string s1;
54             cin >> s1;
55             passwd = s1;
56             cout << "new passwd is set successfully..." << endl; 
57             break;
58         }
59         if(times < 2)
60         cout << "password input error. Please re-enter again:";
61         times++;
62     }
63     if(times >= 3) cout << "passwd input error. Please try affter a while." << endl;
64 }
65 
66 void User::print_info(){
67     cout << "name: " << name << endl;
68     cout << "passwd: ";
69     string s1(passwd.length(), '*');
70     cout << s1 << endl;
71     cout << "email: " << email << endl;
72 }

User.hpp

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

task5.cpp

测试代码：

 

 

 

标签：std,const,cout,对象,void,Complex,实验,using
From： https://www.cnblogs.com/gkd-gkd/p/16786400.html