ArrayList Vs Vector

Difference between ArrayList and Vector

ArrayList	Vector
1) ArrayList is non-synchronized which means multiple threads can work on ArrayList at the same time.	1) Vector is  synchronized which means multiple threads can’t work on vector at the same time.
2) ArrayList increments (3/2 +1)of current array size(almost 50% of current capacity) if total  number of element exceeds than its capacity.	2) Vector increments 100% means doubles the array size if total number of element exceeds than its capacity.
3) ArrayList  is introduced in JDK 1.2.so it is not a legacy class.	3) Vector is a legacy class.
4) ArrayList gives better performance as it is non-synchronized.	4) Vector operations gives poor performance as they are synchronized( thread-safe).
5) ArrayList uses Iterator interface to traverse the elements.	5) Vector uses Enumeration as well as Iterator interface to traverse the elements.

 

Similarities between ArrayList and Vector

1. Both Vector and ArrayList use growable array data structure.
2.  Both are ordered collection classes as they maintain the elements insertion order.
3. Both Vector and ArrayList allows duplicate and null values.
4.  Both grows and shrinks automatically when number of element exceeds than its capacity.

 

ArrayList Example

import java.util.*;
public class MyArrayList {
   public static void main(String args[]) {
      // ArrayList declaration
      ArrayList<Integer> al =new ArrayList<Integer>();
      // Adding elements to the Arraylist
      al.add(1);
      al.add(2);
      al.add(3);
      al.add(1);
      al.add(5);
      //Displaying Arraylist elements
      System.out.println(al);
    }
}

Output:

[1, 2, 3, 1, 5]

Vector Example

import java.util.*;
public class MyVector {
   public static void main(String args[]) {
      // Vector declaration
      Vector<Integer> vt =new Vector<Integer>();
      // Adding elements to the Vector
      vt.add(1);
      vt.add(10);
      vt.add(30);
      vt.add(40);
      vt.add(10);
      //Displaying Vector elements
      System.out.println(vt);
    }
}

Output:

[1, 10, 30, 40, 10]