Unit 3 If statements Quiz

Pick the value that best completes the sentence: A boolean variable has _______ value(s).

• only one valid

• two valid

• three valid

• only invalid

What mathematical symbol/word does the symbol && in java represent?

• and

• or

• average

• absolute value

What does the symbol ! mean in a boolean expression?

• Always use 0 for x

• Always true

• Never true

• Not

If x = 5, y = 10 and z = 10, the expression

(x < y) && !(y ==z)

will return the value of _______________.

• true

• false

• null

• cannot be determined

What will be the output for the following program segment?

int num = 20;

if (num > 0)

if (num % 5 == 0)

System.out.println(num);

else System.out.println(num + " is negative ");

• 20

• 4

• 4 is negative

• 20 is negative

What line of code would replace the following algebraic inequality?

 $-3\ \le\ x\ <\ 5$  

• -3 < x || x < 5 

• -3 <= x || x < 5

• -3 < x && x < 5 

• -3 < = x && x < 5 

Consider the following code assuming the variables have been properly defined.

String mystery_word = new String ("Comp Sci ");

System.out.println ("Enter a word ");

String word = reader.nextLine();

// compare the word to the mystery word

if (*** line of code goes here ****)

System.out.println ( "your word matches");

else

System.out.println ("The words do not match");

What is the proper code to compare the two words?

• ! (word.equals(mystery_word))

• ! ( word == mystery_word)

• (word.equals(mystery_word))

• (word == mystery_word)

You use a single equal sign (=) when you are ___________________

• assigning a value to a variable

• comparing values in an if statement

• only solving an mathematical problem

You use a double equal sign (==) when you are ___________________

• comparing two values

• setting the value of a variable

• only solving a mathematical expression

Find the value of the following expression given the following values:

boolean correct = true;

int x = 5;

int y = 10;

(x > y) && correct

• True

• False