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Challenge exercise Write a method isPrime (int n) that returns true if the parameter n is a prime number, and false if it is not. To implement the method, you can write a while loop that divides n by all numbers between 2 and
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- An obvious continuation is to use random numbers to create namesfor the stars and planets. Instead of creating random strings of characters, names usually follow certain rules. Select a set of real-world names (e.g. from J.R.R. Tolkien’sworld) and invent a set of rules that they follow. Design and implement a methodthat creates new names based on the set of rules and random numbers.arrow_forwardCan you implement the Student class using the concepts of encapsulation? A solution is placed in the "solution" section to help you, but we would suggest you try to solve it on your own first. You are given a Student class in the editor. Your task is to add two fields: ● String name ● String rollNumber and provide getter/setters for these fields: ● getName ● setName ● getRollNumber ● setRollNumber Implement this class according to the rules of encapsulation. Input # Checking all fields and getters/setters Output # Expecting perfectly defined fields and getter/setters. There is no need to add constructors in this class.arrow_forwardImplement a new concat method in the String class you worked on for HW2. The method should return a new String object that represents the text you would end up with if the argument String were "added onto the end of" this String. For example, in the code below, the String object answer should represent the text "bookstore" and true should be printed the screen. char[] bookA = {'b', 'o', 'o', 'k'}; char[] storeA = {'s', 't', 'o', 'r', 'e'}; char[] bookstoreA = {'b', 'o', 'o', 'k', 's', 't', 'o', 'r', 'e'}; String book = new String(bookA); String store = new String(storeA); String bookstore = new String(bookstoreA); String answer = book.concat(store); System.out.println(answer.equals(bookstore)); In the text area below, type in your definition of the concat method. (In other words, type in the code that should replace the //TODO comment.) Your code cannot call any methods. public class String { private char[] data; public String(char[] value) { data = new…arrow_forward
- Note that you can only use recursion to solve Q1 and you cannot use any loop. You are free to add helper methods, but you are not allowed to change the method header.Question 1: Crazy seriesIn this session, you need to implement the crazy series method. In the crazy series, you will be given a starting number. Then, you need to times 2 for each number until the number is greater than 100. After the number is greater than 100, you need to divide 3 until we reach the number is less than 5. Note that the input number must be greater than 0, and you are not allowed to use loop here.For example,crazySeries(10) should return ArrayList [10.0, 20.0, 40.0, 80.0, 160.0, 53.333333333333336, 17.77777777777778, 5.9259259259259265, 1.9753086419753088]crazySeries(5) should return ArrayList [5.0, 10.0, 20.0, 40.0, 80.0, 160.0, 53.333333333333336, 17.77777777777778, 5.9259259259259265, 1.9753086419753088]crazySeries(1) should return ArrayList [1.0, 2.0, 4.0, 8.0, 16.0, 32.0, 64.0, 128.0,…arrow_forwardAdd a method called multiplesOfFive to the Exercise class. The method must have a void return type and take a single int parameter called limit. In the body of the method, write a while loop that prints out all multiples of 5 between 10 and limit (inclusive) on a single line. For instance, if the value of limit were 15 then the method will print: 10 15 You can use the printEvenNumbers method that is already in the Exercise class as an example to help you work out how to complete this method. In the main method of the Main class, add a call on the Exercise object to your multiplesOfFive method that prints the multiples of 5 between 10 and 25. Add a method called sum to the Exercise class. The method must have a void return type and take no parameters. In the body of the method, write a while loop to sum the values 1 to 10 and print the sum once the loop has finished. In the main method of the Main class, add a call on the Exercise object to your sum method. Check that it prints: 55 Add…arrow_forwardYou have a card on which the letter J is written on one side and K on the other. You want to seeall of the possible ways the card will land if you drop it n times. Write a recursive method thatprints each session of dropping the cards with J's and K's. For example if you drop it 4 times in agiven session, all possible ways to drop it are as follows (in exactly the specified order): J J J JJ J J KJ J K JJ J K KJ K J JJ K J KJ K K JJ K K KK J J JK J J KK J K JK J K KK K J JK K J KK K K JK K K Karrow_forward
- You have a card on which the letter J is written on one side and K on the other. You want to seeall of the possible ways the card will land if you drop it n times. Write a recursive method thatprints each session of dropping the cards with J's and K's. For example if you drop it 4 times in agiven session, all possible ways to drop it are as follows (in exactly the specified order): (java code)arrow_forwardThe “odd/even factorial” of a positive integer n is represented as n!! and is defined recursively as: a. (n)*(n-2)*(n-4)………*(2) if n is even. For example, 6!! = 6*4*2 = 48 b. (n)*(n-2)*(n-4)*…….*(5)*(3)*(1) if n is odd. For example, 7!! = 7*5*3*1 = 105. Come up with a recursive definition for n!! and use it to guide you to write a method definition for a method called “oddevenfact” that recursively calculates the odd/even factorial value of its single int parameter. The value returned by “oddevenfact” is a long.arrow_forwardFor this problem you will write a method that prints out a pyramid. The boxes in each layer of the pyramid are stacked directly on top of one another (i.e. not offset between two boxes below). For example, below are shown two pyramids, one with base 5 and one with base 6. [] [][] [][][] [][][][] [][][][][] [][][][][][]arrow_forward
- write a method that calculate the average of all numbers from 1 to n, return a double valuearrow_forwardIn java, Write a method checks if a given matrix is a unit matrix. An N x N unit matrix is a matrix of N rows and N columns where all the diagonal elements are ‘1’s and all the remaining elements are ‘0’s. The method should take a 2D array of integers as argument and return a Boolean which is true/false depending on whether the matrix corresponding to the 2D array is a unit matrix or not. Test the method in the ‘main’ method. For problems asking for 'methods', you need to write the method, and the 'main' method which is used as a 'driver' to test the given method.arrow_forwardFor this problem you will write a method that computes the number of boxes in a pyramid of boxes based on the number of boxes in the base. The boxes in each layer of the pyramid are stacked directly on top of one another (i.e. not offset between two boxes below). For example, below are shown two pyramids, one with base 5 and one with base 6. [] [][] [][][] [][][][] [][][][][] [][][][][][] Implement and test the computePyramidBoxes() method in the PyramidBoxCount class. When testing the computePyramidBoxes() method you should be sure to have at least one test method for each base case and at least one test method for each recursive case in your program.arrow_forward
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