Java Collections Framework Quiz

<p>ArrayList (C)</p> Signup and view all the answers

<p>HashMap does not maintain order, while TreeMap maintains a sorted order (C)</p> Signup and view all the answers

<p>When you require ordered iteration of elements (B)</p> Signup and view all the answers

<p>Map (B)</p> Signup and view all the answers

<p>It converts a collection to an array (C)</p> Signup and view all the answers

<p><code>ArrayList</code> (D)</p> Signup and view all the answers

<p>It provides a way to iterate over a collection's elements (C)</p> Signup and view all the answers

<p><code>clear()</code> (C)</p> Signup and view all the answers

<p>It represents a key-value pair in a map (B)</p> Signup and view all the answers

<p><code>Collections.synchronizedCollection()</code> (A)</p> Signup and view all the answers

<p>A <code>LinkedHashSet</code> maintains the insertion order of elements, while a <code>HashSet</code> does not (D)</p> Signup and view all the answers

<p><code>Collections.synchronizedMap()</code> (D)</p> Signup and view all the answers

<p>1 5 8 2 (C)</p> Signup and view all the answers

<p>2 (A)</p> Signup and view all the answers

<p>[3, 5] (C)</p> Signup and view all the answers

<p>shuffle() (B)</p> Signup and view all the answers

<p>toArray() (A)</p> Signup and view all the answers

<p>put() (B)</p> Signup and view all the answers

<p>clear() (B)</p> Signup and view all the answers

<p>An error will be thrown. (D)</p> Signup and view all the answers

<p>dequeue() removes and returns the next item in line while peek() returns the next item without removing it (D)</p> Signup and view all the answers

<p>size() (B)</p> Signup and view all the answers

<p>All of the mentioned (A)</p> Signup and view all the answers

<p>16, 0.75 (A)</p> Signup and view all the answers

<p>2 8 5 1 (B)</p> Signup and view all the answers

<p>[A, B, C] 3 (A)</p> Signup and view all the answers

<p>False (D)</p> Signup and view all the answers

<p>clear() (A)</p> Signup and view all the answers

<p>package (A)</p> Signup and view all the answers

<p>java.lang (A)</p> Signup and view all the answers

<p>package packageName; (D)</p> Signup and view all the answers

<p>import packageName.*; (C)</p> Signup and view all the answers

<p>Yes (C)</p> Signup and view all the answers

<p>The package name followed by the class name (B)</p> Signup and view all the answers

<p>java.io (A)</p> Signup and view all the answers

<p>java.graphics (C)</p> Signup and view all the answers

<p>12345 (D)</p> Signup and view all the answers

<p>set() (B)</p> Signup and view all the answers

<p>[B, C] (D)</p> Signup and view all the answers

<p>true (A)</p> Signup and view all the answers

<p>{C=8, B=2} (C)</p> Signup and view all the answers

<p>HashSet (A)</p> Signup and view all the answers

<p>SortedList (D)</p> Signup and view all the answers

<p>fill() (C)</p> Signup and view all the answers

Provides a unified way to represent and manipulate collections of data in Java.

A List in the Java Collections Framework; elements are stored in a specific order and can repeat.

A List allows duplicate elements, while a Set does not. This means each element in a Set must be unique.

The ArrayList class is a common way to create a List in Java.

The Deque interface (Double-ended Queue) is a type of list that provides efficient insertion and removal at both ends (front and back).

A Map stores data in key-value pairs, where each key is unique.

The HashMap class is a common way to implement a Map in Java.

A HashMap does not maintain order, while a TreeMap does, based on the natural ordering of keys or the comparator provided.

Converts a collection to an array in Java.

Provides a way to step through elements in a collection, one at a time.

Removes all elements from a collection.

Represents a key-value pair in a map (dictionary-like structure).

Thread-safe collections that can be accessed by multiple threads without data corruption.

LinkedHashSet preserves insertion order; HashSet does not.

Creates a thread-safe version of a map.

Reverses the order of elements in a list.

Reverses the order of elements in a LinkedList.

Accesses the element at a specific index in a Vector.

Pop removes and returns the top element, push adds an element to the top.

Randomly rearranges elements in a list.

Creates a new array from an ArrayList.

Adds a key-value pair to a map.

Removes all key-value pairs from a map.

Returns the index of the element before the current position.

Setting up an array by assigning initial values to its elements. In Java, you can declare an array with a specific size and then use a loop to assign values.

Arranging the elements of an array in a specific order, either ascending or descending. The Java Arrays.sort() method handles this task.

A method that allows you to modify an existing element within a LinkedList object. It replaces a specific element at a particular index with a new value.

Removes the first element from a LinkedList object. It can be used when you need to process the elements sequentially or you want to remove the first entry in the list.

A method in the Vector class that checks if the Vector contains any elements. It returns true if the Vector is empty, false otherwise.

Used to delete an entry from a Hashtable. It takes a key as input and removes the associated key-value pair.

The HashSet class is one of the implementations of the Set interface in Java. Sets ensure that all elements are unique.

A group of built-in classes and interfaces in Java that let you store, manage, and access collections of objects. It provides a generic way to represent and manipulate data collections.

The dequeue() method removes and returns the next item from a queue. The peek() method returns the next item in the queue without removing it.

The size() method of the ArrayList class is used to obtain the current number of elements in the ArrayList.

Legacy classes in Java are older, less efficient, or have been superseded by more modern alternatives. These include Stack, Hashtable, and Vector.

A HashSet starts with an initial capacity of 16 and a load factor of 0.75. The load factor determines when the capacity of the set is automatically increased.

The LinkedList class maintains the order of elements as they are added, preserving the order of insertion.

A HashSet is a collection that stores unique elements, and it doesn't maintain any order. It uses a hash table for efficient storage and retrieval.

No, the HashSet class doesn't have a get(Object o) method because it's not designed for retrieving elements based on their index. The primary purpose of a HashSet is to store and search for unique elements efficiently.

The LinkedList class implements a linked list data structure, providing a linked chain of nodes for storing elements.

A mechanism to organize related classes and interfaces into a logical grouping, promoting code reusability and avoiding name conflicts. Packages also enforce access control.

A keyword used to bring classes from other packages into the current program's scope.

The package keyword followed by the package name, used to declare a package at the beginning of a Java file.

A package can be further divided into smaller packages, creating a hierarchical structure.

The complete name of a class, including its package name. It's used to uniquely identify a class.

A set of pre-written Java classes and packages that provide common functionality like input/output, math operations, and utilities.

The java.lang package is automatically imported into every Java program, providing fundamental classes.

Without importing, you can use a class from another package by specifying its fully qualified name.