c++ vector insert before xth element code example

Example 1: how to append one vector to another 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());

Example 2: insert at position in vector c++

// where v is the vector to insert, i is
// the position, and value is the value

v.insert(v.begin() + i, v2[i])