Difference between arraylist and vector

 

• Vector was introduced in  first version of java . that's the reason only vector is legacy class.
• ArrayList was introduced in java version1.2, as part of java collections framework.
• Synchronization and Thread-Safe:

• Vector is  synchronized. Synchronization and thread safe means at a time only one thread can access the code .In Vector class all the methods are synchronized .That's why the Vector object is already synchronized when it is created .
• ArrayList is not synchronized.

How To Make ArrayList synchronized:

• We have direct method in collections class to make Arrraylist as Synchronized.
• List li=new ArrayList();
• Collections.synchrinizedlist(li);

Automatic Increase in Capacity:

• A Vector defaults to doubling size of its array.
• ArrayList increases it's size by 50%.

Performance:

• Vector is slower than ArrayaList.
• ArrayList is faster than Vector.