add to vector c++

vector<int> a;
vector<int> b;
// Appending the integers of b to the end of a 
a.insert(a.end(), b.begin(), b.end());

// vector::push_back
#include <iostream>
#include <vector>

int main ()
{
  std::vector<int> myvector;
  int myint;

  std::cout << "Please enter some integers (enter 0 to end):\n";

  do {
    std::cin >> myint;
    myvector.push_back (myint);
  } while (myint);

  std::cout << "myvector stores " << int(myvector.size()) << " numbers.\n";

  return 0;
}

vector_name.push_back(element_to_be_added);

#include<bits/stdc++.h>
using namespace std;

int main()
{
    vector<int> vec = {20, 30, 50, 60};
    vec.insert(vec.begin()+2, 40);
    for(auto x:vec)
    {
        cout << x << " ";
    }

    return 0;
}

std::vector<int> v;
v.push_back(10);