c++

#include <iostream>
#include <string>
#include <vector>
#include <list>
using namespace std;

//重载函数
int ok(void)
{
    cout << "ok1" << endl;
    return 0;
}

int ok(int m)
{
    cout << "OK: " << m << endl;
    return 0;
}

//对于类下的静态成员，因为其是共享的，所以其他对象都可以改变静态成员
class zhu {
    friend int set_score(void);   //友元函数，可以访问类里面的私有数据
private:  //不能由外部直接访问，可以由public部分函数访问
    char *name;
    int num;
    int score;
    static int add(int num) {
        return ++num;
    }
public:
    static int pl;
    int pk;
    static int del(int num)    //静态变量函数不能访问非静态变量以及非静态函数
    {
        num = add(num);
        num = add(num);
        return --num;
    }
    int input_arg(char *name0, int num0, int score0);
    int is_upto_60(void);
    zhu() = default;   //构造函数
    ~zhu();  //析构函数

};

zhu zhu0;
zhu zhu1;

//zhu::zhu(void)   //num = i
//{
//    cout << "class zhu create" << endl;
//}

zhu::~zhu(void)
{
    cout << "class zhu delete"<< endl;
}
int set_score(void)
{
    char a[6] = "zhuyj";
    zhu1.name = a;
    zhu1.num = 2;
    zhu1.score = 55;
    return 0;
}
int zhu::input_arg(char *name0, int num0, int score0)
{
    name = name0;
    num = num0;
    score = score0;
    return 0;
}

int zhu::is_upto_60(void)
{
    if (score >= 60)
        return 1;
    else
        return 0;
}

int zhu::pl = 0;
int main(void) {
    vector<string> vb{ "jsdfk","sdhj"};
    
    int a{1};
    int b = a + 1;
    cout << "b = " << b << endl;
    string c = "abcdf";
    string h;
    string d(c);
    string e("sdhj");
    string f(6, 'g');
    string g = e + f;
    cout << "d = " << d << endl;
    cout << "g = " << g << endl;
    if (h.empty())
        cout << "h is empty" << endl;
    if (g.empty())
        cout << "g is empty" << endl;
    else
        cout << "g's size is " << g.size() << endl;
    string s1;
    for (auto c : g)
        cout << c << endl;
    cout << "input string" << endl;
    //while (getline(cin, s1)) 
     //    cout << s1 << endl;
    ok();
    ok(3);
    //类
    char y[10] = "zhuyanjun";
    zhu0.input_arg(y, 1, 65);
    if (zhu0.is_upto_60())
        cout << "zhu0 ok" << endl;
    else
        cout << "zhu0 NO" << endl;
    if (zhu1.is_upto_60())
        cout << "zhu1 ok" << endl;
    else
        cout << "zhu1 NO" << endl;
    zhu::pl = 1;    //静态的可以这么赋值，因为整个文件只有一个pl，独立于具体实例化的类存在
    //zhu0.pl = 2;   //这样也是可以的
    //zhu::pk = 9;    //错误，pk变量必须依赖实例化的类存在
    cout << "pl = " << zhu0.pl << endl;
    int m;
    m = zhu::del(5);
    cout << "m = " << m << endl;
    //容器
    vb.push_back("shu");
    //使用迭代器访问容器内元数
    auto y1 = vb.begin();
    auto y2 = vb.end();   //迭代器end指向的是容器尾元数之后的元数（不存在）
    cout << "vb'begin is " << *y1<< endl;
    cout << "vb'end is " << *(--y2) << endl; 
    //vb.pop_back();
    auto h0 = find(vb.cbegin(), vb.cend(),"shu");
    cout << "shu  " << (h0 == vb.cend() ? "is not present" : "is present") << endl;
    vb.erase(y2);
    vb.clear();
    if (!vb.empty()) {
        auto f1 = vb.front();
        auto f2 = vb.back();
        cout << "vb'begin is " << f1 << endl;
        cout << "vb'end is " << f2 << endl;
    }

    list<int> ilist(10, 42);   //建立双链表ilist，有10个int, 值都是42
    ilist.resize(15);    //将5个0添加到ilist链表尾部
    ilist.resize(25, -1); //将10个-1添加到ilist尾部
    ilist.resize(5);     //删除ilist尾部的20个元数


    while (1);
    return 0;
}