import java.util.Vector; public class VectorClass { public static void main(String[] args) { Vector vtr = new Vector(20); //initialCapacity = 20 is the initial capacity, after filling the 20 elements // initialCapacity will become 2*20 = 40 (before filling 21st element) vtr.add(20); System.out.println(vtr.get(0)); System.out.println(vtr.size()); // Size of vtr is still 1 because only one element is there int arr[] = new int[20]; System.out.println(arr.length); // note here, size is method in vector and length is property of array // Size of vector is 1 and length of array is 20 } }