实验一

#ifndef COMPLEX_H
#define COMPLEX_H
#include<iostream>
#include<cmath>
class Complex {
private:
    float real;
    float imag;
public:
    Complex(float a = 0, float b = 0) :real(a), imag(b) {};
    Complex(const Complex& p) :real(p.real), imag(p.imag) {};
    float get_real() const{ return real; };
    float get_imag() const{ return imag; };
    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 float abs(const Complex c);
};
void Complex::show() const{
    std::cout << real;
    if (imag < 0)
        std::cout << imag << 'i' << std::endl;
    else if (imag > 0)
        std::cout << '+' << imag << 'i' << std::endl;
    else
        std::cout << std::endl;
}
void Complex::add(const Complex c) {
    real += c.real;
    imag += c.imag;
}
Complex add(const Complex c1, const Complex c2) {
    Complex c;
    c.real = c1.real + c2.real;
    c.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;
    else
        return false;
}
float abs(const Complex c) {
    float out;
    out = c.real * c.real + c.imag * c.imag;
    out = sqrt(out);
    return out;
}
#endif

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

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;
}

 

 

#ifndef USER_H
#define USER_H
#include<iostream>
#include<string>
using namespace std;
class User {
private:
    string name;
    string passwd;
    string email;
    static int n;
public:
    User(string a, string b = "111111", string c = "\0") :name(a), passwd(b), email(c) { n++; };
    void set_email();
    void change_passwd();
    void print_info();
    static void print_n() {
        cout << "there are " << n << " users." << endl;
    };
};
int User::n = 0;
void User::set_email() {
    cout << "Enter email address:";
    cin >> email;
    cout << "email is set successfully..." << endl;
}
void User::change_passwd() {
    cout << "Enter old password:";
    string old;
    cin >> old;
    int i;
    for (i = 0; i < 2; i++) {
        if (old == passwd){
            cout << "Enter new passwd:";
            cin >> passwd;
            cout << "new passwd is set successfully..."<<endl;
            break;
        }
        else{
            cout << "password input error.Please re-enter again:";
            cin >> old;
        }
    }
    if (i == 2)
        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;
}

#endif

#include "User.h"
#include <iostream>

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();
}