c 2b 2b vector size

1#include <vector>
2
3int main () {
4    std::vector<int> v;
5    auto size = v.size();
6}

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}

1#include <iostream>
2#include <vector>
3using namespace std;
4
5int main() {
6  //vector element size
7  const int size = 4; 
8  //vector with int data type
9  //all elements are equal to 4
10  vector<int> myVect (size, 4);
11
12  for (int i=0; i<size; i++) {
13    cout << "Vector index(" << i <<") is: "<< myVect[i] << endl; 
14  }
15  return 0;
16}

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

1#include <iostream>
2#include <vector>
3
4using namespace std;
5
6int main(void) {
7   vector<int> v;
8
9   cout << "Initial vector size = " << v.size() << endl;
10
11   v.resize(5, 10);
12   cout << "Vector size after resize = " << v.size() << endl;
13
14   cout << "Vector contains following elements" << endl;
15   for (int i = 0; i < v.size(); ++i)
16      cout << v[i] << endl;
17
18   return 0;
19}

1vectorName.size();