试验2 类与对象（2）

试验任务4

Complex.cpp

#pragma once
#include<iostream>
#include<cmath>
class Complex {

public:
Complex();
Complex(double newreal);
Complex(double newreal, double newimag);
Complex(const Complex& C);
double get_real() const;
double get_imag()const;
void show()const;
void add(const Complex &a);

friend Complex add(const Complex& a, const Complex& b);
friend bool is_equal(Complex& a, const Complex& b);
friend double abs(const Complex& a);
private:
double real;
double imag;

};

Complex::Complex() :real(0), imag(0) {}
Complex::Complex(double newreal) :real(newreal), imag(0) {}
Complex::Complex(double newreal, double newimag) :real(newreal), imag(newimag) {}
Complex::Complex(const Complex& C) {
real = C.real;
imag = C.imag;
}

double Complex::get_real () const {
return real;

}
double Complex::get_imag() const {
return imag;
}
void::Complex::show()const {
std::cout << real << imag ;
if (imag != 0)
std::cout << "i";
}
void Complex::add(const Complex &a) {

real = real + a.real;
imag = imag + a.imag;

}

Complex add(const Complex& a, const Complex& b) {
Complex c;
c.real = a.real + b.real;
c.imag = a.imag + b.imag;

return c;

}

bool is_equal(Complex& a, const Complex& b) {
if (a.real == b.real && a.imag == b.imag)
return true;
else
return false;

 

}
double abs(const Complex&obj) {

return sqrt(obj.real * obj.real + obj.imag * obj.imag);

}

试验任务4 源码

#include <iostream>
#include "Complex.hpp"
void test() {
    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;
}
int main() {
    test();
}

运行结果

试验任务5User.hpp

#pragma once
#include<string>
#include<iostream>
using namespace std;
class User {
public:
    User(string h,string p,string k) {
        name = h;
        passwd = p;
        email = k;
        n++;
    };
    User(string h) {
        n++;
        name = h;
        passwd = "111111";
        email ="";
    }
    void set_email();
    void change_passwd() ;
    void print_info();
    static void print_n();
    static int n;
private:
    string name;
    string passwd;
    string email;

};
int User::n;

void User::print_info() {
    

    cout << "name:   " << name << endl;
    cout << "passwd: " <<"******" << endl;
    cout << "email:  " << email << endl;
}

void User::change_passwd() {
    string h;
    int i;
    cout << "Enter old passworld:";
    for (i = 0; i < 3; i++)
    {
        cin >> h;
        if (h == passwd)
        {
            cout << "Enter new passworld:";
                cin >> passwd;
                cout << "new passworld is set successfully..."<<endl;
                break;
        }
        else {
            if(i<=1)
            cout << "passworld input error.please re-enter again:";
        }
    }
    if (i == 3)
        cout << "passworld input error.please try afer a while"<<endl;

}
void User::set_email() {

    cout << "Enter email address:";
    cin >> email;
    cout << "email is set successfully..." << endl;

}
 void User::print_n(){

     cout << "There are " << n << " users"<<endl;


}

试验任务5 源码

#include "User.hpp"
#include <iostream>
// 测试User类
void test() {
    using std::cout;
    using std::endl;
    cout << "testing 1......\n";
    User user1("Jonny", "92197", "xyz@hotmail.com");
    user1.print_info();
    cout << endl
        << "testing 2......\n\n";
    User user2("Leonard");
    user2.change_passwd();
    user2.set_email();
    user2.print_info();
    cout << endl;
     User::print_n() ;
}
int main() {
    test();
}

 

 

 

 

实验总结

对于基本的语法使用还不太熟练

注意const static  的使用方法