c 2b 2b vector initialize size

1vector<vector<int>> v(10, vector<int>(10));

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<vector<vector<double>>> f(3, vector<vector<double>>(4, vector<double>(5)));
2

1std::vector<std::string> vec(20000);
2

1vector<Entry> array(1000);//size of 1000
2