length of a vector code example

Example 1: vector length c++

#include <vector>

int main () {
    std::vector<int> v;
    auto size = v.size();
}

Example 2: vector length formula

||v|| = sqrt(a^2+b^2)

Example 3: vector length java

import java.util.*;
class sizeaf
{
  public static void main(String args[])
  {
    Vector v = new Vector();
    v.add(1);
    v.add(2);
    v.add(3);
    v.add(4);
    System.out.println("Size : "+v.size());
  }
}