concat two vectors c++

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

int main() {
    vector<int> vector1 = {1, 2, 3};
    vector<int> vector2 = {4, 5, 6};

    vector1.insert(vector1.end(), vector2.begin(), vector2.end());

    for (int num : vector1) {
        cout << num << " ";
    }

    return 0;
}