Collections Framework In Java — Part 1 MCQs with Explanations

To provide a unified architecture for representing and manipulating collections is the correct answer to “What is the purpose of the Java Collections Framework”. This question is standard in competitive examination syllabi for Collections Framework In Java.

`List` is the correct answer to “Which interface in the Java Collections Framework represents an ordered collection of elements that can contain duplicate values”. This question is standard in competitive examination syllabi for Collections Framework In Java.

A `List` allows duplicate elements, while a `Set` does not is the correct answer to “What is the primary difference between a `List` and a `Set` in the Java Collections Framework”. This question is standard in competitive examination syllabi for Collections Framework In Java.

`ArrayList` is the correct answer to “Which class is typically used to implement a `List` in the Java Collections Framework”. This question is standard in competitive examination syllabi for Collections Framework In Java.

`Deque` is the correct answer to “In the Java Collections Framework, which interface extends the `List` interface to provide more efficient insertions and deletions in the middle of the list”. This question is standard in competitive examination syllabi for Collections Framework In Java.

To store key-value pairs is the correct answer to “What is the purpose of the `Map` interface in the Java Collections Framework”. This question is standard in competitive examination syllabi for Collections Framework In Java.

`HashMap` is the correct answer to “Which class is typically used to implement a `Map` in the Java Collections Framework”. This question is standard in competitive examination syllabi for Collections Framework In Java.

A `HashMap` does not maintain order, while a `TreeMap` does is the correct answer to “What is the primary difference between a `HashMap` and a `TreeMap` in the Java Collections Framework”. This question is standard in competitive examination syllabi for Collections Framework In Java.

`Set` is the correct answer to “In the Java Collections Framework, which interface represents a collection of unique elements with no duplicates”. This question is standard in competitive examination syllabi for Collections Framework In Java.

`HashSet` is the correct answer to “Which class is typically used to implement a `Set` in the Java Collections Framework”. This question is standard in competitive examination syllabi for Collections Framework In Java.

A `LinkedHashSet` maintains insertion order, while a `HashSet` does not is the correct answer to “What is the primary difference between a `HashSet` and a `LinkedHashSet` in the Java Collections Framework”. This question is standard in competitive examination syllabi for Collections Framework In Java.

`Set` is the correct answer to “Which interface in the Java Collections Framework represents a collection of elements with no specific order”. This question is standard in competitive examination syllabi for Collections Framework In Java.

A `Queue` represents a single-ended queue, while a `Deque` represents a double-ended queue is the correct answer to “What is the primary difference between a `Queue` and a `Deque` in the Java Collections Framework”. This question is standard in competitive examination syllabi for Collections Framework In Java.

`ArrayDeque` is the correct answer to “Which class is typically used to implement a `Deque` in the Java Collections Framework”. This question is standard in competitive examination syllabi for Collections Framework In Java.

`Collections` is the correct answer to “In the Java Collections Framework, which class allows you to create a synchronized (thread-safe) collection”. This question is standard in competitive examination syllabi for Collections Framework In Java.

`SortedSet` is the correct answer to “Which interface in the Java Collections Framework extends the `Set` interface and represents a collection of elements stored in a sorted order”. This question is standard in competitive examination syllabi for Collections Framework In Java.

It defines a comparison function for ordering elements is the correct answer to “What is the purpose of the `Comparator` interface in Java Collections Framework”. This question is standard in competitive examination syllabi for Collections Framework In Java.

`TreeSet` is the correct answer to “Which class is typically used to implement a `SortedSet` in the Java Collections Framework”. This question is standard in competitive examination syllabi for Collections Framework In Java.

`Stack` is the correct answer to “In the Java Collections Framework, which interface represents a last-in, first-out (LIFO) stack of elements”. This question is standard in competitive examination syllabi for Collections Framework In Java.

A `Stack` uses a LIFO (Last-In-First-Out) order, while a `Queue` uses a FIFO (First-In-First-Out) order is the correct answer to “What is the primary difference between a `Stack` and a `Queue` in the Java Collections Framework”. This question is standard in competitive examination syllabi for Collections Framework In Java.

`add()` is the correct answer to “In Java, which method is used to add an element to a collection in the Java Collections Framework”. This question is standard in competitive examination syllabi for Collections Framework In Java.

It converts a collection to an array is the correct answer to “What is the purpose of the `toArray()` method in the Java Collections Framework”. This question is standard in competitive examination syllabi for Collections Framework In Java.

`Collections` is the correct answer to “In the Java Collections Framework, which class provides methods to manipulate the size of a list and its elements”. This question is standard in competitive examination syllabi for Collections Framework In Java.

It provides a way to iterate over a collection's elements is the correct answer to “What is the purpose of the `Iterator` interface in the Java Collections Framework”. This question is standard in competitive examination syllabi for Collections Framework In Java.

`clear()` is the correct answer to “Which method is used to remove all elements from a collection in the Java Collections Framework”. This question is standard in competitive examination syllabi for Collections Framework In Java.

It represents a key-value pair in a map is the correct answer to “What is the purpose of the `Map.Entry` interface in the Java Collections Framework”. This question is standard in competitive examination syllabi for Collections Framework In Java.

`Collections.synchronizedCollection()` is the correct answer to “In the Java Collections Framework, which method is used to obtain a synchronized (thread-safe) version of a collection”. This question is standard in competitive examination syllabi for Collections Framework In Java.

`Collections.synchronizedMap()` is the correct answer to “In Java, which method is used to obtain a synchronized (thread-safe) map from an existing map in the Java Collections Framework”. This question is standard in competitive examination syllabi for Collections Framework In Java.

It reverses the order of elements in a list is the correct answer to “What is the purpose of the `Collections.reverse()` method in the Java Collections Framework”. This question is standard in competitive examination syllabi for Collections Framework In Java.

ensureCapacity() is the correct answer to “Which of these method can be used to increase the capacity of ArrayList object manually”. This question is standard in competitive examination syllabi for Collections Framework In Java.

[D, A, B, C] is the correct answer to “What will be the output of the following Java code snippet? import java.util.*; class Linkedlist { public static void main(String args[]) { LinkedList obj = new LinkedList(); obj.add("A"); obj.add("B"); obj.add("C"); obj.addFirst("D"); System.out.println(obj); } }”. This question is standard in competitive examination syllabi for Collections Framework In Java.

A group of objects is the correct answer to “What is Collection in Java”. This question is standard in competitive examination syllabi for Collections Framework In Java.

singletonList() is the correct answer to “Which of these methods can convert an object into a List”. This question is standard in competitive examination syllabi for Collections Framework In Java.

2 is the correct answer to “What will be the output of the following Java program? import java.util.*; class Maps { public static void main(String args[]) { HashMap obj = new HashMap(); obj.put("A", new Integer(1)); obj.put("B", new Integer(2)); obj.put("C", new Integer(3)); System.out.println(obj.get("B")); } }”. This question is standard in competitive examination syllabi for Collections Framework In Java.

Reference equality is the correct answer to “What is the premise of equality for IdentityHashMap”. This question is standard in competitive examination syllabi for Collections Framework In Java.

All of the mentioned is the correct answer to “Which of these is static variable defined in Collections”. This question is standard in competitive examination syllabi for Collections Framework In Java.

1 2 5 8 is the correct answer to “What will be the output of the following Java program? import java.util.*; class Collection_Algos { public static void main(String args[]) { LinkedList list = new LinkedList(); list.add(new Integer(2)); list.add(new Integer(8)); list.add(new Integer(5)); list.add(new Integer(1)); Iterator i = list.iterator(); Collections.reverse(list); Collections.sort(list); while(i.hasNext()) System.out.print(i.next() + " "); } }”. This question is standard in competitive examination syllabi for Collections Framework In Java.

Stack is LIFO; Queue is FIFO is the correct answer to “What is the difference between Queue and Stack”. This question is standard in competitive examination syllabi for Collections Framework In Java.

{3, 4} is the correct answer to “What will be the output of the following Java code? import java.util.*; class Bitset { public static void main(String args[]) { BitSet obj1 = new BitSet(5); BitSet obj2 = new BitSet(10); for (int i = 0; i < 5; ++i) obj1.set(i); for (int i = 3; i < 13; ++i) obj2.set(i); obj1.and(obj2); System.out.print(obj1); } }”. This question is standard in competitive examination syllabi for Collections Framework In Java.

Front and read pointers point to the first element is the correct answer to “What are the use of front and rear pointers in CircularQueue implementation”. This question is standard in competitive examination syllabi for Collections Framework In Java.