Java Programming: Calling Methods

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In the Date class, which method should be used to change the value of the instance variable 'day'?

setDay() (correct)

changeDay()

updateDay()

getDay()

For object 'birthday' of the Date class, what is the correct way to retrieve the month using an accessor method?

int month = birthday.getMonthValue();

int theMonth = birthday.setMonth();

int month = birthday.retrieveMonth();

int theMonth = birthday.getMonth(); (correct)

How many instance variables are there in the Date class?

4

2

3 (correct)

1

Which type of method is the getMonth() method in the Date class?

Accessor method Signup and view all the answers

To complete the setDay() method in the Date class, what parameter should be passed?

newDay Signup and view all the answers

What should be returned by the getDay() method in the Date class?

'day' Signup and view all the answers

What will be the output of the code snippet provided?

true true Signup and view all the answers

Which of the following expressions will evaluate to false?

game instanceof Soccer Signup and view all the answers

Which statement will generate a compilation error?

System.out.println(title.toUpperCase()) Signup and view all the answers

Which of the following statements will cause a compilation error?

Resizable shape = new Resizable(){}; Signup and view all the answers

Given the declaration Resizable circle = new Circle(5.5);, which of the following statements will compile successfully?

circle.resize(3.0); Signup and view all the answers

'InstanceOf' operator in Java is used for:

Checking if an object is an instance of a particular class or interface Signup and view all the answers

What is the output of the program segment in the given text?

Opening datafile.txt...Reading data...Done. Signup and view all the answers

What should be inserted in the missing statement in method openFile() to prompt the user for a valid file name?

inputFile = new Scanner(new File(in.next())); Signup and view all the answers

Which exception is caught by the catch block in Practice 7.19 if an IOException occurs?

FileNotFoundException Signup and view all the answers

What happens if the file in Practice 7.20 contains only two integer values instead of three?

InputMismatchException is generated. Signup and view all the answers

In Practice 7.18, what happens if 'datafile.txt' does not exist?

A FileNotFoundException occurs. Signup and view all the answers

What does 'array = array + array;' in the text do?

Produces an error due to invalid syntax. Signup and view all the answers

What will be the output of the code segment processing input one character at a time using a Scanner object?

9 Signup and view all the answers

In the second code segment processing an input file one line at a time, what is the purpose of the condition 'if (Character.isDigit(input.charAt(0)))'?

To check if the first character of each line is a digit Signup and view all the answers

If the delimiter used in the third code segment breaks the string 'apple,orange,banana' into three tokens, what would be the value of 'count' printed at the end?

3 Signup and view all the answers

What is the significance of 'data.useDelimiter(""")' in the third code segment?

It sets the delimiter to be a double quote Signup and view all the answers

If 'data.hasNextLine()' returns false in the second code segment, what can be inferred?

All lines in the input file have been processed Signup and view all the answers

What does 'count++' signify in all three code segments?

'count' increments for each line read from the input file Signup and view all the answers

Which method call is illegal using a reference variable of the BaseballPlayer class?

player1.setBattingAvg(.258); Signup and view all the answers

Which method is overridden in the BaseballPlayer class?

display Signup and view all the answers

How can private superclass variables be accessed in subclass methods in Java?

Using public getters for the private variables in the superclass Signup and view all the answers

How can you call an overridden superclass method within a subclass method in Java?

By using the super keyword followed by the method name Signup and view all the answers

What statement completes the display() method in the BaseballPlayer class to include superclass properties?

System.out.println(super.getName() + " " + super.getSalary()); Signup and view all the answers

Which statement correctly invokes the superclass constructor from the BaseballPlayer class constructor?

super(theName, theSalary); Signup and view all the answers

Consider class Soccer as a subclass of Sport. Which assignment of objects is invalid?

Soccer mySport = new Sport(); Signup and view all the answers

What will be printed when this statement is executed within a Java code segment: `BaseballPlayer bp = new BaseballPlayer(); bp.display();`?

"null 0 0" Signup and view all the answers

What will be printed when this Java code segment is executed: `Player p = new BaseballPlayer(); p.display();`?

It will call Player's display method. Signup and view all the answers

What happens when `p.display()` is called where `Player p = new Player();`?

It will print Player's display information. Signup and view all the answers