Java Chapter 5

How many times will the following do-while loop be executed? int x = 11; do { x += 20; } while (x > 100);

1

What will be the value of x after the following code is executed? int x = 10; while (x < 100)

100

What will be the value of x after the following code is executed? int x, y = 15; x = y--;

15

In all but rare cases, loops must contain within themselves

A way to terminate

How many times will the following for loop be executed? for (int count = 10; count <= 21; count++) System.out.println("Java is great!!!");

12

What will be the value of x after the following code is executed? int x = 10; do { x *= 20; } while (x < 5);

200

What will be the value of x after the following code is executed? int x = 10, y = 20; while (y < 100) { x += y; y += 20; }

210

What will be printed after the following code is executed? for (int number = 5; number <= 15; number +=3) System.out.print(number + ", ");

5, 8, 11, 14

This type of loop will always be executed at least once.

Post-test loop

This is a value that signals when the end of a list of values has been reached.

Sentinel

If a loop does not contain within itself a way to terminate, it is called

An infinite loop

Which of the following will open a file named MyFile.txt and allow you to append data to its existing contents? A) FileWriter fwriter = new FileWriter("MyFile.txt"); PrintWriter outFile = new PrintWriter(fwriter); B) FileWriter fwriter = new FileWriter("MyFile.txt", true); PrintWriter outFile = new PrintWriter(fwriter); C) PrintWriter outfile = new PrintWriter("MyFile.txt", true); D) PrintWriter outfile = new PrintWriter(true, "MyFile.txt");

B) FileWriter fwriter = new FileWriter("MyFile.txt", true); PrintWriter outFile = new PrintWriter(fwriter);

A loop that executes as long as a particular condition exists is called a(n) _____.

Conditional loop

A loop that repeats a specific number of times is known as a(n) _____________.

Count-controlled loop

Assuming that inputFile references a Scanner object that was used to open a file, which of the following statements will read an int from the file? A) int number = inputFile.next(); B) int number = inputFile.integer(); C) int number = inputFile.readInt(); D) int number = inputFile.nextInt();

D) int number = inputFile.nextInt();

This is an item that separates other items.

Delimiter

True or False The do-while loop is a pre-test loop.

False

True or False In a for loop, the control variable can only be incremented.

False

True or False The do-while loop is a pre-test loop.

False

True or False\ When the break statement is encountered in a loop, all the statements in the body of the loop that appear after it are ignored, and the loop prepares for the next iteration.

False

A sentinel value ____________ and signals that there are no more values to be entered.

Is a special value that cannot be mistaken as a member of the list

In the following code, what values could be read into number to terminate the while loop? Scanner keyboard = new Scanner(System.in); System.out.print("Enter a number: "); int number = keyboard.nextInt(); while (number < 100 || number > 500) { System.out.print("Enter another number: "); number = keyboard.nextInt(); }

Numbers in the range 100 through 500

This is a sum of numbers that accumulates with each iteration of a loop.

Running total

You can use this method to determine whether a file exists.

The File class's exists method

In the following code, what values could be read into number to terminate the while loop? Scanner keyboard = new Scanner(System.in); System.out.print("Enter a number: "); int number = keyboard.nextInt(); while (number < 100 && number > 500) { System.out.print("Enter another number: "); number = keyboard.nextInt(); }

The boolean condition can never be true

True or False When you pass the name of a fi le to the PrintWriter constructor, and the file already exists, it will be erased and a new empty file with the same name will be created.

True

True or False The do-while loop must be terminated with a semicolon.

True

When you open a file with the PrintWriter class, the class can potentially throw an IOException True or False

True

This type of loop is ideal in situations where the exact number of iterations is known.

for loop

Which of the following are pre-test loops:

while, for