C++ vector ------- push_back(elem), push_back()

#include <string.h>
#include <vector>
#include <iostream>
using namespace std;

int main()
{
    vector<double>v1;	//创建一个向量存储容器 double
    vector<double>v2;	//创建一个向量存储容器

    cout<<"v1: ";
    for(int i=0;i<10;i++) // push_back(elem)在数组最后添加数据elem
    {
        v1.push_back(i);
        cout<<v1[i]<<",";
    }

    cout<<endl<<"v2: ";
    for(int i=0;i<10;i++) // push_back(elem)在数组最后添加数据elem
    {
        v2.push_back(i);
        cout<<v2[i]<<",";
    }

    double arr[10];
    cout<<endl<<"arr=v1+v2: ";
    for(int i=0;i<10;i++)
    {
        arr[i] = v1[i] + v2[i];
        cout<<arr[i]<<",";
    }


    /////////////////////////////////////////////////
    for(int i=0;i<5;i++)//pop_back()去掉数组最后一个数据
    {
        v1.pop_back();
    }

    cout<<"\nAfter pop: ";

    for(int i=0;i<v1.size();i++)//size()容器中实际数据个数
    {
        cout<<v1[i]<<",";
    }


    return 0;
}
#include <string.h>
#include <vector>
#in