c++vector容器

#include "iostream"
#include "vector"

using namespace std;

class AA
{
public:
    int m_bh;//编号
    string m_name;//姓名

    AA()
    {
        cout<<"默认构造函数AA().\n";
    }

    AA(const int &bh,const string&name):m_bh(bh),m_name(name)
    {
        cout<<"构造函数，name="<<m_name<<"。\n";
    }

    AA(const AA& g):m_bh(g.m_bh),m_name(g.m_name)
    {
        cout<<"拷贝构造函数，name="<<m_name<<"。\n";
    }
    ~AA(){cout<<"析构函数。\n";}

};
int main(){
    //1)创建一个空的vector容器
    vector<int> v1;
    cout<<"v1.capacity()="<<v1.capacity()<<", v1.size()="<<v1.size()<<endl;
    //2)创建vector容器，元素个数为n(容量和实际大小都是n)
    vector<int> v2(8);
    cout<<"v2.capacity()="<<v2.capacity()<<", v2.size()="<<v2.size()<<endl;
    //7)使用统一初始化列表创建容器。
    vector<int>v3({1,5,2,4,3});
    for (int ii = 0; ii < v3.size(); ++ii) {
        cout<<v3[ii]<<" ";
    }
    cout<<endl;

    v3.data()[0]=8;//数组表示法
    v3.data()[1]=7;
    *(v3.data()+2)=5;//
    *(v3.data()+3)=5;


    for (int ii = 0; ii < v3.size(); ++ii) {
        cout<<v3[ii]<<" ";
    }
    cout<<endl;

    int a;
    vector<int> v;

    a=1;v.push_back(a);
    a=2;v.push_back(a);
    a=3;v.push_back(a);

    for (int ii = 0; ii < v.size(); ++ii) {
        cout<<v[ii]<<" ";
    }
    cout<<endl;

    vector<AA> n;
    AA aa(18,"西施");
    //n.push_back(aa);
    //n.emplace_back(aa);
    n.emplace_back(18,"西施");//在容器的尾部追加一个元素，...用于构造元素。c++
    cout<<"bh="<<n[0].m_bh<<",name="<<n[0].m_name<< endl;

    vector<vector<int>> v4;

    vector<int> v5;

    v5={1,2,3,4,5};//用
    v4.push_back(v5);

    v5={11,12,13,14,15,16,17};
    v4.push_back(v5);

    v5={21,22,23};
    v4.push_back(v5);

    for (int ii=0;ii<v4.size();ii++) {
        for (int jj = 0; jj < v4[ii].size() ;jj++) {
            cout<<v4[ii][jj]<<" ";//像二维数组一样使用容器、
            cout<<endl;
        }

    }
}

输出：

v1.capacity()=0, v1.size()=0
v2.capacity()=8, v2.size()=8
1 5 2 4 3
8 7 5 5 3
1 2 3
构造函数，name=西施。
构造函数，name=西施。
bh=18,name=西施
1
2
3
4
5
11
12
13
14
15
16
17
21
22
23
析构函数。
析构函数。