MCQs on Java Collections Framework

What is the Java Collections Framework?

• A set of algorithms for sorting and searching data

• A collection of classes and interfaces for handling groups of objects

• A framework for Java database management

• A GUI toolkit for Java

Which of the following is not a part of the Java Collections Framework?

• ArrayList

• HashMap

• StringBuffer

• TreeSet

What is the default capacity of a Vector in Java?

• 5

• 10

• 15

• 20

Which method in the ArrayList class is used to retrieve an element at a specific index?

• get()

• fetch()

• retrieve()

• indexOf()

What is the key difference between ArrayList and Vector?

• Vector is synchronized, whereas ArrayList is not

• ArrayList is synchronized, whereas Vector is not

• Vector does not allow duplicates, whereas ArrayList does

• ArrayList can store only primitive data types

Which Java class implements the Stack data structure?

• LinkedList

• Stack

• Queue

• HashMap

Which interface is used to iterate over a collection in Java?

• Enumeration

• Iterable

• Iterator

• All of the above

What is the function of the hasNext() method in Iterator?

• Checks if the iterator has reached the last element

• Returns the next element in the iteration

• Checks if there are more elements to iterate over

• Removes the last accessed element

Which of the following is a thread-safe class in Java?

• ArrayList

• LinkedList

• HashMap

• Hashtable

What is the purpose of StringTokenizer in Java?

• To perform mathematical calculations on strings

• To break a string into smaller tokens based on delimiters

• To convert a string into an integer

• To store multiple strings in a list