Java Online Quiz – Test your knowledge in 7 min

What guarantees type-safety in a collection?

HashSet internally uses?

The most used interfaces from the collection framework are?

The root interface of Java collection framework hierarchy is –

Which of those is synchronized?

ArrayList implements that of the following?

Which of those permits the storage of the many null values?

nextIndex() and previousIndex() are methods of which interface?

Vector extends that of these?

LinkedList implements?

In Iterator, nextElement() method of Enumeration has been changed to:

Enumeration returned by Vector is?

From Java five onwards, that one among these is suggested to replace Hashtable?

Which doesn’t permit to store a null value?

Iterator returned by Vector is?

What describes an algorithm performs in best, average or worse case scenarios?

State the search time complexity of an ordered array.

Name the map that should be kept in a multi-threading environment to keep up the natural order of keys?

TreeMap implements?

Which list class should be most popular in a multi-threading environment, considering performance constraint?