find vector size in c 2b 2b

1#include <vector>
2
3int main() {
4  std::vector<int> myVector = { 666, 1337, 420 };
5  
6  size_t size = myVector.size(); // 3
7  
8  myVector.push_back(399); // Add 399 to the end of the vector
9  
10  size = myVector.size(); // 4
11}

1vector<int> a;
2//to directly find the size of the vector;
3//use  a.size(;
4
5cout <<" " << a.size();

1vectorName.size();