CMSC 132 Quiz 1 Worksheet The first Quiz of the course will be on Wednesday Sept 7 during your lab discussion session The following list provides more information about the quiz You will have 25 minutes to complete the quiz It will be a written quiz not using any computer It will be closed book closed notes and no calculator is allowed Answers must be neat and legible We recommend that you use pencil and eraser The quiz will be based on the exercises you will find below The following exercises cover the material to be included in Quiz 1 Solutions to these exercises will not be provided but you are welcome to discuss your solutions with TAs and instructors during office hours Problem 1 1 Consider the following two classes Oven and Microwave public class Oven protected String make public void turnOn System out println Oven On public class Microwave extends Oven public double power public void turnOn System out println Micro On public void turnOn int thePower power thePower System out println Micro On with power Based on these classes answer the following questions a The following main is in a class named Driver The Driver Oven and Microwave classes all belong to the same package Indicate whether each of the underlined statements below is valid or invalid Consider each one in isolation earlier errors do not affect later statements public static void main String args Oven p new Oven These two variable declarations are correct Oven m new Microwave p turnOn 10 VALID INVALID p make GT VALID INVALID p power 200 VALID INVALID m turnOn 20 VALID INVALID Microwave k Microwave m k turnOn 200 VALID INVALID Microwave make TU VALID INVALID Oven make TU VALID INVALID Oven turnOn VALID INVALID b The following statements are also part of main Show the output produced by each If an error results write ERROR Oven v1 new Microwave v1 turnOn Output Microwave v2 new Oven v2 turnOn Output Problem 2 Consider the interface Wireless and class Network below public interface Wireless public double getRange public class Network private String name private int numComputers public Network String n int c name n numComputers c public Network Network n name new String n name numComputers n numComputers public String getName return name public int getNumComputers return numComputers Implement a class named WirelessNetwork that extends the class Network and implements the Wireless interface It has a single private double instance variable called maxRange which represents the wireless network s maximum signal range Your class should contain the following public methods a Constructor This constructor takes three arguments A String parameter representing the network name a number of computers and a double representing the maximum range b Default Constructor The constructor will initialize a WirelessNetwork object with the values COMP NAME 1 and 50 Note You must use the constructor from part a in your implementation of this constructor c equals A boolean method equals Object o which tests this object for equality with another object To be equal both objects must be of the same class recall the method getClass and have the same name number of computers and maximum range d Interface method s implement any method s necessary to satisfy the Wireless interface The wireless device range is just the value of maxRange Problem 3 Write a method called clean that has the following prototype public static String clean String data int number The method returns a two dimensional array with those rows of data whose length is greater than or equal to number
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