Java Collections Framework Quiz

What is the purpose of the toArray() method in the Java Collections Framework?

In the Java Collections Framework, which class provides methods to manipulate the size of a list and its elements?

What is the purpose of the Iterator interface in the Java Collections Framework?

Which method is used to remove all elements from a collection in the Java Collections Framework?

What is the purpose of the Map.Entry interface in the Java Collections Framework?

In the Java Collections Framework, which method is used to obtain a synchronized (thread-safe) version of a collection?

What is the primary difference between a HashSet and a LinkedHashSet in the Java Collections Framework?

What is the purpose of the Collections.reverse() method in the Java Collections Framework?

What will be the output of the Java code snippet that prints a HashSet containing both a Long and an Integer with the value 10?

What exception is thrown when two threads attempt to modify a TreeSet simultaneously?

What will be the output of the given Java program that sorts an array initialized within a loop?

Which of these standard collection classes is NOT an implementation of the List interface?

What is a unique characteristic of the LinkedHashSet in Java?

Which method is correctly used for inserting and deleting items from a queue in Java?

What result does the program demonstrate when comparing two ArrayList objects for equality?

What is the worst-case complexity for accessing an element in an ArrayList?

When executing a program using HashMap, what will be the printed output based on the provided key-value pairs?

What will the output of the provided Hashtable Java code be when checking for a value that is not present?

Which standard collection class provides a dynamically resizable array in Java?

Which class object utilizes keys to store values in Java?

What is the expected outcome of executing Java code that prints a Date object?

Which class objects can be utilized to create a dynamic array in Java?

What is the main programming error in the Array class when trying to initialize the array?

When the ArrayList 'obj2' is modified using the add method, how does this affect the equality check with 'obj1'?

What will be the output of the Java program that uses a TreeSet to add the elements '3', '9', '1', '4', and '8'?

In the following Java code, what will be the output? int array[] = new int; for (int i = 5; i > 0; i--) array[5-i] = i; Arrays.fill(array, 1, 4, 8);

What will be the output of this code after clearing a Hashtable? Hashtable obj = new Hashtable(); obj.put('A', new Integer(3)); obj.put('B', new Integer(2)); obj.clear(); System.out.print(obj.size());

Which method is utilized to retrieve elements from a Properties object at a specific location?

Which method is appropriate for adding an element with a corresponding key to a map in Java?

What is the proper way to remove duplicates from a List in Java?

What will be the output of the provided Java program that initializes an array and sorts it?

Which iterator is specifically designed for use with List collections in Java?

Which method is used to move to the next element in a collection iterator?

Is a HashMap considered an ordered collection in Java?

What will be the output of the Java program that removes the first element from a LinkedList after adding 'A', 'B', and 'C'?

What does the output of the provided Java Vector program returning obj.isEmpty() indicate after all elements are removed?

What will the output be after removing an entry from a Hashtable that contains keys A, B, and C?

Which of the following classes implements the Set interface in Java?

Which interface listed is not part of Java's collection framework?

Which method is used to set all elements of an array to a specified value in Java?

What will be the output of the program that tries to store elements in the Properties object and retrieves keys?

Which of the following classes does not implement the Map interface?

Which method would you use to retrieve an element from a BitSet at a specific index?

Which exception is thrown when attempting to remove an element from a collection that is not in the proper state?

What is the method of the HashSet class that allows you to add a new element?

Given a sorted array, what will be the result of a binary search for the number 4 in this array if the array contains numbers 1, 2, 3, 5?

What will be the output of the ArrayList program after ensuring capacity and trimming to size?

Which interface guarantees that all elements are unique?