实验1

实验1

#include<iostream>
#include<string>
#include<vector>
int main()
{
    using namespace std;
    string s1;
    string s2{"c plus plus"};
    string s3{s2};
    string s4=s2;
    s1="oop";
    vector<string> v1;
    v1.push_back(s1);
    v1.push_back(s2+"1");
    v1.push_back(s3+"2");
    v1.push_back(s4+"3");
    cout<<"output1:"<<endl;
    for(auto item:v1)
        cout<<item<<endl;
    cout<<"output2:"<<endl;
    for(auto p=v1.begin();p!=v1.end();++p)
        cout<<*p<<endl;
    cout<<"output3:"<<endl;
    for(auto i=0;i<v1.size();++i)
        cout<<v1[i]<<endl;
    vector<string>v2{v1.rbegin(),v1.rend()};
    cout<<"v2:"<<endl;
    for(auto item:v2)
        cout<<item<<endl;
}

 

 

#include<iostream>
#include<string>
#include<vector>
#include<cmath>
#include<cstdlib>
#include<time.h>
template<typename T>
void output(const T& obj)
{
    for (auto item : obj)
        std::cout << item << " ";
    std::cout << std::endl;
}
int main()
{
    using namespace std;
    vector<int>v1{ 1,9,8,4 };
    v1.insert(v1.begin(), 2022);
    v1.insert(v1.end(), 2023);
    cout << "v1: ";
    output(v1);
    v1.pop_back();
    v1.erase(v1.begin());
    cout << "v1: ";
    output(v1);
    vector<string>v2{ "《1984》","《动物农场》","《美丽新世界》" };
    cout << "v2: ";
    output(v2);
}

实验2

#include<iostream>
using std::cout;
using std::endl;
class Point {
public:
    Point(int x0 = 0, int y0 = 0);
    Point(const Point& P);
    ~Point() = default;
    int get_x()const { return x; }
    int get_y()const { return y; }
    void show()const;
private:
    int x, y;
};
Point::Point(int x0, int y0) :x{ x0 }, y{ y0 }{
    cout << "constructor called." << endl;
}
Point::Point(const Point& p) : x{ p.x }, y{ p.y }{
    cout << "copy constructor called." << endl;
}
void Point::show()const {
    cout << "(" << x << "," << y << ")" << endl;
}
int main()
{
    Point p1(9, 2);
    p1.show();
    Point p2 = p1;
    p2.show();
    Point p3{ p2 };
    p3.show();
    cout << p3.get_x() << endl;
}

 

 实验3

#include<iostream>
#include<iomanip>
using std::cout;
using std::endl;
class Clock {
public:
    Clock(int h = 0, int m = 0, int s = 0);
    Clock(const Clock& t);
    ~Clock() = default;
    void set_time(int h, int m = 0, int s = 0);
    void show_time()const;
private:
    int hour, minute, second;
};
Clock::Clock(int h, int m, int s) :hour{ h }, minute{ m }, second{ s }{
    cout << "constructor called" << endl;
}
Clock::Clock(const Clock& t) : hour{ t.hour }, minute{ t.minute }, second{ t.second }{
    cout << "copy constructor called" << endl;
}
void Clock::set_time(int h, int m, int s) {
    hour = h;
    minute = m;
    second = s;
}
void Clock::show_time()const {
    using std::setw;
    using std::setfill;
    cout << setfill('0') << setw(2) << hour << ":" << setw(2) << minute << ":" << setw(2) << second << endl;
}
Clock reset()
{
    return Clock(0, 0, 0);
}
int main()
{
    Clock c1(11, 50, 0);
    c1.show_time();

    c1 = reset();
    c1.show_time();

    Clock c2(c1);
    c2.set_time(6);
    c2.show_time();
}

实验4

#include<iostream>
class X {
public:
    X();
    ~X();
    X(int m);
    X(const X& obj);
    X(X&& obj) noexcept;
    void show()const;
private:
    int data;
};
X::X() :data{ 42 } {
    std::cout << "default constructor called.\n";
}
X::~X() {
    std::cout << "destructor called.\n";
}
X::X(int m) :data{ m } {
    std::cout << "constructor called.\n";
}
X::X(const X& obj) :data{ obj.data } {
    std::cout << "copy constructor called.\n";
}
X::X(X&& obj)noexcept :data{ obj.data } {
    std::cout << "move constructor called.\n";
}
void X::show()const {
    std::cout << data << std::endl;
}
int main() {
    X x1;
    x1.show();
    X x2{ 2049 };
    x2.show();
    X x3{ x1 };
    x3.show();
    X x4{ std::move(x2) };
    x4.show();
}

分析：

创建X x1时，默认构造函数被调用，函数执行完成后对x1所占的资源进行了清理；

创建X x2{2049}时，构造函数被调用，函数执行完成后对x2进行了清理；

创建X x3{x1}时，复制构造函数被调用，函数执行完成后对x3所占资源进行了清理；

创建X x4{std::move（x2）}时，移动构造函数被调用，执行完成后对x4进行了清理；

实验5

#include<iostream>
#include<iomanip>
class Rectangle
{
public:
    Rectangle(float l = 2.0, float w = 1.0) :length{ l }, width{ w }{}
    Rectangle(const Rectangle& obj) :
        length{ obj.length }, width{ obj.width }{}
    ~Rectangle() = default;
    float len() const { return length; }
    float wide()const { return width; }
    float area()const { return length * width; }
    float circumference()const { return 2 * (length + width); }
    void resize(int time);
    void resize(int l_times, int w_times);
private:
    float length, width;
};
void Rectangle::resize(int n)
{
    length *= n;
    width *= n;
}
void Rectangle::resize(int l_times, int w_times)
{
    length *= l_times;
    width *= w_times;
}
void output(const Rectangle &rect) {
    using namespace std;
    cout << "矩形信息:\n";
    cout << fixed << setprecision(2);
    cout << std::left << setw(8)<<"长："  << rect.len() << endl;
    cout << std::left << setw(8) << "宽：" << rect.wide() << endl;
    cout << std::left << setw(8) << "面积：" << rect.area() << endl;
    cout << std::left << setw(8) << "周长：" << rect.circumference() << endl;
    cout << endl;
}
int main() {
    Rectangle rect1;
    output(rect1);
    Rectangle rect2(10, 5);
    output(rect2);
    Rectangle rect3(rect1);
    rect3.resize(2);
    output(rect3);
    rect3.resize(5, 2);
    output(rect3);
}

原数据结果

修改数据后