Arrays: create an array of a given type and populate its values. Use of for loop to traverse through an array to do the following : to print the elements one by one, to search the array for a given value. ArrayList: create an ArrayList containing elements of a given type . Use some of the common ArrayList methods to manipulate contents of the ArrayList. Write methods that will take an ArrayList as its parameter/argument ; and/or return an ArrayList reference variable as its return type. Searching for an object in an Array: Loop through the ArrayList to extract each object and to check if this object’s attribute has a given value. Explain how and why interfaces are used in Java Collection Framework. Explain the major differences between a Stack and a Queue. Be able to use stack and queue methods. What is meant by O(N) notation? Express the complexity of a given code using the O(N) notation.

Q6.! Problem Description: Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to the target. You may assume that each input would have exactly one solution, and you may not use the same element twice. You can return the answer in any order.  Ananda.!

17. Phone Book ArrayList Write a class named PhoneBookEntry that has fields for a person's name and phone number. The class should have a constructor and appropriate accessor and mutator methods. Then write a program that creates at least five PhoneBookEntry objects and stores them in an ArrayList. Use a loop to display the contents of each object in the ArrayList.

Define a class called Book. This class should store attributes such as the title, ISBN number, author, edition, publisher, and year of publication. Provide get/set methods in this class to access these attributes. Define a class called Bookshelf, which contains the main method. This class should create a few book objects with distinct names and store them in an ArrayList. This class should then list the names of all books in the ArrayList. Enhance the program by providing a sort function, which will sort the books in ascending order of their year of publication. Create a few more Bookobjects with the same names but with different edition numbers, ISBNs, and years of publication. Add these new Book objects to the ArrayList, and display the book list sorted by book name; for duplicate books of the same name, sort the list by year of publication. (Hint: You will need to define a comparator class that takes two Book objects as parameters of the compareTo This method should do a two-step…