if we can make ArrayList synchronized then what is the need of Vector? similarly, if we can make HashMap synchronized then what is the need of Hashtable?
The reasons why both
ArrayList exist is historical: the
Vector class was there in the Java 1, while
ArrayLists were added in Java 1.2 as a "lighter-weight" alternative. Java keeps
Vector for backward compatibility; it should not be used unless you want a synchronized version of an