Exam1-Chapter (1-4)

When two Strings are compared using the compareTo method, the cases of the two strings are not considered.

false

Which of the following is valid?

float w; w = 1.0f;

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

for loop

If chr is a character variable, which of the following if statements is written correctly?

if (chr == 'a')

If a loop does not contain within itself a way to terminate, it is called a(n):

infinite loop

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

Which Scanner class method reads a String?

nextLine()

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

numbers in ranges of 100-500.

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

post-test loop

A local variable's scope always ends at the closing brace of the block of code in which it is declared.

true

In a switch statement, each of the case values must be unique.

true

The expression tested by an if statement must evaluate to:

true or false

Assume that inputFile references a Scanner object that was used to open a file. Which of the following while loops shows the correct way to read data from the file until the end of the file is reached?

while (inputFile.hasNext()) { }

If x has been declared an int, which of the following statements is invalid?

x = 1,000;

What will be the values of x and y as a result of the following code? int x = 25, y = 8; x += y++;

x = 33, y = 9

To do a case insensitive compare which of the following could be used to test the equality of two strings, str1 and str2?

(str1.equalsIgnoreCase(str)) and (str1.compareToIgnoreCase(str2) == 0)

What would be the value of discountRate after the following statements are executed? double discountRate; char cusType = 'B'; switch (custType) { case 'A': discountRate = .08; break; case 'B' discountRate = 0.6; case 'C' discountRate = .04; default : discountRate = 0.0; }

0.0

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

1

What does the following code display? double x = 12.3798146; System.out.printf("%.2f\n", x);

12.38

What will be the value of x after the following code is executed? int x = 75; int y = 60; if (x > Y) x = x - y;

15

If str1 and str2 are both Strings, which of the following expressions will correctly determine whether they are equal? (1) (str1 == str2) (2) str1.equals(str2) (3) (str1.compareTo(str2) == 0)

2 and 3

What will be the value of charges after the following code is executed? double charges, rate = 7.00; int time = 180; charges = time <= 119 ? rate * 2 : time/ 60.0 * rate;

21.00 180/60.0 * 7.00 = 21.00

What is the result of the following expression? 25/4+4*10%3

7

What does the following code display? int d = 9, e = 12; System.out.printf("%d %d\n", d, e);

9 12

In all but rare cases, loops must contain within themselves:

A way to terminate.

In Java, it is standard practice to capitalize the first letter of:

Class names

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

Counter-controlled loop.

Which of the following statements correctly creates a Scanner object for keyboard input?

Scanner keyboard = new Scanner(System.in);

Which one of the following methods would you use to convert a string to a double?

Double.parseDouble()

Which of the following will open a file named MyFile.txt and allow you to read data from it?

File file = new File("MyFile.txt"); Scanner inputFile = new Scanner(file);

Which of the following will open a file named MyFile.txt and allow you to append data to its existing contents?

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

Which of the following is not a rule that must be followed when naming identifiers?

Identifiers can contain spaces.

The switch statement is a:

Multiple alternative decision structure

What would be printed out as a result of the following code? System.out.println("The quick brown fox" + "jumped over the \n" "slowing moving hen.");

Nothing; This is errors

In the following Java statement what value is stored in the variable name? String name = "John Doe";

The memory address where "John Doe" is located

A file must always be opened before using it and closed when the program is finished using it.

True

The if/else statement will execute one group of statements if its boolean expression is true or another group if its boolean expression is false.

True

When you pass the name of a file 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

A for loop normally performs which of these steps?

a) Initializes a control variable to a starting value b) Tests the control variable by comparing it to a maximum/minimum value and terminate when the variable reaches that value c) Updates the control variable during each iteration

A block of code is enclosed in a set of:

braces { }