c++

  1 #include <iostream>
  2 #include <string>
  3 #include <vector>
  4 #include <list>
  5 using namespace std;
  6 
  7 //重载函数
  8 int ok(void)
  9 {
 10     cout << "ok1" << endl;
 11     return 0;
 12 }
 13 
 14 int ok(int m)
 15 {
 16     cout << "OK: " << m << endl;
 17     return 0;
 18 }
 19 
 20 //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
 21 class zhu {
 22     friend int set_score(void);   //友元函数，可以访问类里面的私有数据
 23 private:  //不能由外部直接访问，可以由public部分函数访问
 24     char *name;
 25     int num;
 26     int score;
 27     static int add(int num) {
 28         return ++num;
 29     }
 30 public:
 31     static int pl;
 32     int pk;
 33     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
 34     {
 35         num = add(num);
 36         num = add(num);
 37         return --num;
 38     }
 39     int input_arg(char *name0, int num0, int score0);
 40     int is_upto_60(void);
 41     zhu() = default;   //构造函数
 42     ~zhu();  //析构函数
 43 
 44 };
 45 
 46 zhu zhu0;
 47 zhu zhu1;
 48 
 49 //zhu::zhu(void)   //num = i
 50 //{
 51 //    cout << "class zhu create" << endl;
 52 //}
 53 
 54 zhu::~zhu(void)
 55 {
 56     cout << "class zhu delete"<< endl;
 57 }
 58 int set_score(void)
 59 {
 60     char a[6] = "zhuyj";
 61     zhu1.name = a;
 62     zhu1.num = 2;
 63     zhu1.score = 55;
 64     return 0;
 65 }
 66 int zhu::input_arg(char *name0, int num0, int score0)
 67 {
 68     name = name0;
 69     num = num0;
 70     score = score0;
 71     return 0;
 72 }
 73 
 74 int zhu::is_upto_60(void)
 75 {
 76     if (score >= 60)
 77         return 1;
 78     else
 79         return 0;
 80 }
 81 
 82 int zhu::pl = 0;
 83 int main(void) {
 84     vector<string> vb{ "jsdfk","sdhj"};
 85     
 86     int a{1};
 87     int b = a + 1;
 88     cout << "b = " << b << endl;
 89     string c = "abcdf";
 90     string h;
 91     string d(c);
 92     string e("sdhj");
 93     string f(6, 'g');
 94     string g = e + f;
 95     cout << "d = " << d << endl;
 96     cout << "g = " << g << endl;
 97     if (h.empty())
 98         cout << "h is empty" << endl;
 99     if (g.empty())
100         cout << "g is empty" << endl;
101     else
102         cout << "g's size is " << g.size() << endl;
103     string s1;
104     for (auto c : g)
105         cout << c << endl;
106     cout << "input string" << endl;
107     //while (getline(cin, s1)) 
108      //    cout << s1 << endl;
109     ok();
110     ok(3);
111     //类
112     char y[10] = "zhuyanjun";
113     zhu0.input_arg(y, 1, 65);
114     if (zhu0.is_upto_60())
115         cout << "zhu0 ok" << endl;
116     else
117         cout << "zhu0 NO" << endl;
118     if (zhu1.is_upto_60())
119         cout << "zhu1 ok" << endl;
120     else
121         cout << "zhu1 NO" << endl;
122     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
123     //zhu0.pl = 2;   //这样也是可以的
124     //zhu::pk = 9;    //错误，pk变量必须依赖实例化的类存在
125     cout << "pl = " << zhu0.pl << endl;
126     int m;
127     m = zhu::del(5);
128     cout << "m = " << m << endl;
129     //容器
130     vb.push_back("shu");
131     //使用迭代器访问容器内元数
132     auto y1 = vb.begin();
133     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）
134     cout << "vb'begin is " << *y1<< endl;
135     cout << "vb'end is " << *(--y2) << endl; 
136     //vb.pop_back();
137     auto h0 = find(vb.cbegin(), vb.cend(),"shu");
138     cout << "shu  " << (h0 == vb.cend() ? "is not present" : "is present") << endl;
139     vb.erase(y2);
140     vb.clear();
141     if (!vb.empty()) {
142         auto f1 = vb.front();
143         auto f2 = vb.back();
144         cout << "vb'begin is " << f1 << endl;
145         cout << "vb'end is " << f2 << endl;
146     }
147 
148     list<int> ilist(10, 42);   //建立双链表ilist，有10个int, 值都是42
149     ilist.resize(15);    //将5个0添加到ilist链表尾部
150     ilist.resize(25, -1); //将10个-1添加到ilist尾部
151     ilist.resize(5);     //删除ilist尾部的20个元数
152 
153 
154     while (1);
155     return 0;
156 }