Question: Look at the following code: String str1 = "

> Write the first line of a class named Customer, which implements an interface named Relatable.

> If an interface has fields, how are they treated?

> How is an interface different from an abstract class, or any class?

> How is an interface similar to an abstract class?

> What is the purpose of an interface?

> If a class is defined as abstract, what can you not do with the class?

> What is the purpose of an abstract class?

> If a subclass extends a superclass with an abstract method, what must you do in the subclass?

> Look at the following class declarations and answer the questions that follow them: public class Shape { private double area; public void setArea(double a) { area = a; } public double getArea() { return area; } } public class Circle extends Shape { priva

> What is the purpose of an abstract method?

> Write a for loop that calculates the total of the following series of numbers: 130+229+328+⋯301

> Recall the Rectangle and Cube classes discussed earlier, as shown in Figure10-18. 1. Is the following statement legal or illegal? If it is illegal, why? Rectangle r = new Cube(10, 12, 5); 2. If you determined that the statement in part a is legal, are th

> When you create a class, it automatically has a toString method and an equals method. Why?

> Look at the following class definition: public class ClassD extends ClassB { (Member Declarations . . .) } Because ClassD inherits from ClassB, is it true that ClassD does not inherit from the Object class? Why or why not?

> Why is it easy to give package access to a class member by accident?

> What is the difference between private access and package access?

> Why should you avoid making class members protected when possible?

> What is the difference between private members and protected members?

> When a class member is declared as protected, what code may access it?

> How do you prevent a method from being overridden?

> Here is the first line of a class declaration. What is the name of the superclass? What is the name of the subclass? public class Truck extends Vehicle

> Write a for loop that displays the following set of numbers: 0, 10, 20, 30, 40, 50 . . . 1000

> Look at the following declaration: String cafeName = "Broadway Cafe"; String str; Which of the following methods would you use to make str reference the string “Broadwayâ€. startsWith regionMatches substring indexOf

> Modify the method so it performs a case-insensitive test. The method should return true if the argument ends with “ger†in any possible combination of uppercase and lowercase letters.

> Write a method that accepts a reference to a String object as an argument and returns true if the argument ends with the substring “gerâ€. Otherwise, the method should return false.

> Write a loop that counts the number of uppercase characters that appear in the String object str.

> What will the following code display? char var = '$'; System.out.println(Character.toUpperCase(var));

> Write a loop that asks the user, “Do you want to repeat the program or quit? (R/Q)”. The loop should repeat until the user has entered an R or Q.

> What is the purpose of the MIN_VALUE and MAX_VALUE variables that are members of the numeric wrapper classes?

> What wrapper class methods convert a number from decimal to another numbering system? What wrapper classes are these methods a member of?

> What is the output of the following statement? System.out.println(Character.toUpperCase(Character.toLowerCase('A')));

> Write a statement that converts the following integer to a string and stores it in the String object referenced by str: int i = 99;

> Write code that does the following: opens a file named NumberList.txt, uses a loop to write the numbers 1 through 100 to the file, and then closes the file.

> Look at the following string: "dog$cat@bird%squirrel" Write code using the String class’s split method that can be used to extract the following tokens from the string: dog, cat, bird, and squirrel.

> Look at the following string: "/home/rjones/mydata.txt" Write code using the String class’s split method that can be used to extract the following tokens from the string: home , rjones , mydata , and txt.

> Look at the following code: String str = "one two three four"; String[] tokens = str.split(" "); int x = tokens.length; String first = tokens[0]; What value will be stored in x? What value will the first variable reference?

> The following string contains three tokens. What are they? What character is the delimiter? "apples pears bananas"

> How does the StringBuilder class’s replace method differ from the String class’s replace method?

> You wish to change a specific character in a StringBuilder object. What method do you use?

> You wish to delete a specific character from the existing contents of a StringBuilder object. What method do you use?

> You wish to insert a string into the existing contents of a StringBuilder object. What method do you use?

> You wish to add a string to the end of the existing contents of a StringBuilder object. What method do you use?

> Write an if statement that displays the word “digit†if the char variable ch contains a numeric digit. Otherwise, it should display “Not a digit.â€.

> Complete the following program so it displays a random integer in the range of 1 through 10. // Write the necessary import statement(s) here. public class ReviewQuestion15 { public static void main(String[ ] args) { // Write the necessary code here. } }

> Look at the following statement: String city = "Asheville"; Rewrite this statement so that city references a StringBuilder object instead of a String object.

> In a program that makes lots of changes to strings, would it be more efficient to use String objects or StringBuilder objects? Why?

> The String class is immutable. What does this mean?

> Assume that a program has the following declarations: double number = 9.47; String str; Write a statement that assigns a string representation of the number variable to str.

> What will the following code display? String str1 = "William "; String str2 = " the "; String str3 = " Conqueror"; System.out.println(str1.trim() + str2.trim() + str3.trim());

> What is the difference between the getChars and toCharArray methods?

> The + operator, when used with strings, performs the same operation as what String method?

> What is the difference between the getChars and substring methods?

> What is the difference between the indexOf and lastIndexOf methods?

> Write nested loops to draw this pattern:

> Write a statement that converts the contents of the char variable big to lowercase. The converted value should be assigned to the variable little.

> Assume that the following enumerated data type has been declared: enum Letters { Z, Y, X } What will the following code display? if (Letters.Z.compareTo(Letters.X) > 0) System.out.println("Z is greater than X."); else System.out.println("Z is not greater

> Assume that the following enumerated data type has been declared: enum Creatures{ HOBBIT, ELF, DRAGON } What will the following code display? System.out.println(Creatures.HOBBIT + " " + Creatures.ELF + " " + Creatures.DRAGON);

> Look at the following statement, which declares an enumerated data type: enum Flower { ROSE, DAISY, PETUNIA } 1. What is the name of the data type? 2. What is the ordinal value for the enum constant ROSE? For DAISY? For PETUNIA? 3. What is the fully qual

> Look at the following code. Stock stock1 = new Stock("XYZ", 9.65); Stock stock2 = new Stock("SUNW", 7.92); While the equals method is executing as a result of the following statement, what object does this reference? if (stock2.equals(stock1)) System.out

> Describe the limitation of static methods.

> What action is possible with a static method that isn’t possible with an instance method?

> What is the difference between an instance field and a static field?

> Look at the following statements: int[] numbers1 = { 1, 3, 6, 9 }; int[] numbers2 = { 2, 4, 6, 8 }; int result; Write a statement that multiplies element 0 of the numbers1 array by element 3 of the numbers2 array and assigns the result to the result vari

> Write a statement that creates and initializes a double array with the following ­values: 1.7, 6.4, 8.9, 3.1, and 9.2. How many elements are in the array?

> Write an input validation loop that asks the user to enter a number in the range of 1 through 4.

> Show how the double variables temp, weight, and age can be declared in one statement.

> What is the output of the following code? int[] values = new int[5]; for (int count = 0; count < 5; count++) values[count] = count + 1; for (int count = 0; count < 5; count++) System.out.println(values[count]);

> What happens in Java when a program tries to use a subscript that is out-of-bounds?

> What does it mean for a subscript to be out-of-bounds?

> What is the difference between an array’s size declarator and a subscript?

> What is the difference between an ArrayList object’s size and its capacity?

> How do you determine an ArrayList object’s size?

> What would the valid subscript values be in a four-element array of doubles?

> How do you insert an item at a specific location in an ArrayList object?

> How do you retrieve a specific item from an ArrayList object?

> How do you remove an item from an ArrayList object?

> Modify the code you wrote in Question 18 so it adds all of the numbers read from the file and displays their total.

> How do you add items to an ArrayList object?

> Write a statement that creates an ArrayList object and assigns its address to a variable named lizards. The ArrayList should be able to store String objects only.

> Write a statement that creates an ArrayList object and assigns its address to a variable named frogs.

> What import statement must you include in your code in order to use the ArrayList class?

> If a sequential search is performed on an array, and it is known that some items are searched for more frequently than others, how can the contents of the array be reordered to improve the average performance of the search?

> On average, with an array of 20,000 elements, how many comparisons will the sequential search perform?

> Describe the difference between the sequential search and the binary search.

> What’s wrong with the following array declarations? int[ ] readings = new int[−1]; double[ ] measurements = new double[4.5];

> How many times will the selection sort swap the smallest value in an array with another value?

> What value in an array does the selection sort algorithm look for first? When the selection sort finds this value, what does it do with it?

> Write a while loop that lets the user enter a number. The number should be multiplied by 10, and the result stored in the variable product. The loop should iterate as long as product contains a value less than 100.

> A video rental store keeps videos on 50 racks with 10 shelves each. Each shelf holds 25 videos. Declare a three-dimensional array large enough to represent the store’s storage system.

> Recall that we discussed a Rectangle class in Chapter6 . Write code that declares a Rectangle array with five elements. Instantiate each element with a Rectangle object. Use the Rectangle constructor to initialize each object with values for the length a

> 1. Write a statement that declares a String array initialized with the following strings: “Mercuryâ€, “Venusâ€, “Earthâ€, and “Marsâ€. 2. Write a loop that displays the contents of each element in the array you declared in A. 3. Write a loop that

> Write a method named zero, which accepts an int array as an argument and stores the value 0 in each element.

> Look at the following method header: public static void myMethod(double[] array) Here is an array declaration: double[] numbers = new double[100]; Write a statement that passes the numbers array to the myMethod method.

> Look at the following statements: int[] a = { 1, 2, 3, 4, 5, 6, 7 }; int[] b = new int[7]; Write code that copies the a array to the b array.

> A program has the following declaration: double[] values; Write code that asks the user for the size of the array and then creates an array of the specified size, referenced by the values variable.

> A program uses a variable named array that references an array of integers. You do not know the number of elements in the array. Write a for loop that stores −1 in each element of the array.

> Write statements that create the following arrays: 1. A 100-element int array referenced by the variable employeeNumbers. 2. A 25-element double array referenced by the variable payRates. 3. A 14-element float array referenced by the variable miles. 4. A

> In this chapter we used the metaphor of a kite attached to a spool of string to describe the relationship between an object and a reference variable. In this metaphor, does the kite represent an object, or a reference variable?

> Write an if-else statement that displays the String objects title1 and title2 in alphabetical order.

> You hear someone make the following comment: “A blueprint is a design for a house. A carpenter can use the blueprint to build the house. If the carpenter wishes, he or she can build several identical houses from the same blueprint.†Think of this as a