how to find length of vector in java code example

Example: 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());
  }
}