Deck 5: Flow of Control, Part 1: Selection

Question 1

What is the meaning of the operator !=?

A) Is equal to
B) Is greater than
C) Is not equal to
D) Is assigned to

Answer 1

C

Question 2

Which of these takes only one boolean expression?

A) NOT operator
B) AND operator
C) OR operator
D) LOGIC operator

Answer 2

A

Question 3

Which of the following will be executed with the highest precedence?

A) +
B) &&
C) !
D) >=

Answer 3

C

Question 4

A(n) __________ is writing else clauses that do not match any if conditions.

A) Math class
B) abs method
C) if/else statement
D) dangling else

Question 5

To use DeMorgan's Laws, you need to change the AND operator to OR and change the OR operator to AND, and apply the NOT operator (!) to each operand of a logical operator.

Question 6

The conditional operator (?:) can be used in expressions.

Question 7

The conditional operator (?:) has lower precedence than the = operator.

Question 8

The relational operators cannot be used with which of the following?

A) Literal expressions or with object references
B) Boolean expressions or with object references
C) Two operands
D) An expression that evaluates to a primitive numeric type

Question 9

Which of the following choices best describes the statements NOT( A AND B ) = ( NOT A ) OR ( NOT B ) and NOT( A OR B ) = ( NOT A ) AND ( NOT B )?

A) Infinite
B) DeMorgan's Laws
C) Morgan DeLorean's Laws
D) None of these is correct.

Question 10

Which of the following are reasons why some software engineers advocate using curly braces?

A) The curly braces increase clarity.
B) The curly braces highlight the section of code to be executed when the condition is true.
C) Program maintenance is easier.
D) All of these are correct.

Question 11

What error will a compiler generate if you terminate an if statement with a semicolon?

A) An initiate error
B) An error that it is incorrect to place semicolon here
C) A false block error
D) None of these is correct.

Question 12

The _________ of a variable is the region within a program where the variable can be referenced, or used.

A) scope
B) false block
C) if condition
D) None of these is correct.

Question 13

Which of the following will happen if you declare a variable named message after the if statement instead of before it?

A) The scope of message extends from its declaration only until the end of the true block.
B) The scope of message extends from its declaration only until the end of the false block.
C) The scope of message extends from the point where it is declared to the end of the program.
D) The location of the message variable does not affect the output.

Question 14

An if/else statement is appropriate when the data falls into more than two mutually exclusive categories and the appropriate instructions to execute are different for each category.

Question 15

What will result if you have an if statement with two else statements?

A) The dangling else will generate a compiler error "if" without "else".
B) The CompareTo will generate a compiler error "else" without "if".
C) The dangling else will generate a compiler error "else" without "if".
D) None of these is correct.

Question 16

Java ignored indents.

Question 17

Testing an application with if/else statements only once is considered an adequate amount of testing.

Question 18

A test plan includes running the application with different data values designed to execute true statements in the application.

Question 19

The threshold when comparing floating point numbers should be the difference that can be tolerated and still consider the numbers equal.

Question 20

The compareTo method returns:

A) a boolean value.
B) an integer value.
C) either a boolean or an integer value, depending on whether the String object is less than, equal to, or greater than the String argument.
D) an equals value.

Question 21

The __________ method returns true if the data in the parameter object matches the data in the object for which the method was called.

A) boolean
B) compareTo
C) equals
D) SimpleDate

Question 22

Which of the following statements is correct in regards to operator precedence as compared conditional operators?

A) Parentheses operators are lower.
B) Logical OR is lower.
C) Logical AND is lower.
D) Assignment operators are lower.

Question 23

The Conditional Operate (?:) evaluates a condition and contributes one of two values to the expression based on the value of the condition.

Question 24

A conditional operator is a statement that evaluates a condition and contributes one of two values to the expression based on the value of the condition.

Question 25

In the context of a switch statement, the purpose of break statements is to terminate execution of the switch statement.

Question 26

The execution of statements stops before the end of the switch block is reached when a break statement is encountered.

Question 27

The variable operation is not necessary for the switch ( operation ) to work.

Question 28

The following process would work for creating a random roll of a die:
Step 1. Define constant values that will be used to draw the die, position the dots, and display the roll.
Step 2. Set the color to black to draw the dots and use a switch statement on roll to determine which dots to draw.
Step 3. Draw the die itself as red square.
Step 4. Display the roll to verify that you are drawing the correct roll.

Question 29

Which of the following expresses the condition "a is less than b and c."

A) a < b || a < c
B) a < b && c
C) a < b && a < c

Question 30

What is the output of the following code?
Int age = 34;
If ( age > 33 )
System.out.print( 1 );
System.out.println( 2 );

A) 0
B) 1
C) 2
D) 12
E) No output

Question 31

What is the output of the following code?
Int age = 33;
If ( age > 33 )
System.out.print( 1 );
System.out.println( 2 );

A) 0
B) 1
C) 2
D) 12
E) No output

Question 32

What is the output of the following code?
Int age = 30;
If ( age > 33 )
System.out.print( 1 );
Else
System.out.print( 2 );
System.out.println( 3 );

A) 1
B) 2
C) 12
D) 123
E) 23

Question 33

An else block is mandatory after an if.

Question 34

When using an if/else if structure, it is mandatory to have an else block.

Question 35

When using an if/else if structure, we can only use one else if block.

Question 36

A variable that is declared inside the true (or false) block of an if statement is still in scope after we exit that block.

Question 37

When comparing two floating-point numbers for equality, it is safe to use the == operator.

Question 38

When comparing the data in two objects for equality, we typically use the == operator.

Question 39

"!( a && b ) is equivalent to !a || !b" is one of the two __________ laws.

Question 40

With the boolean expression a && b, if a is false, the JVM does not evaluate b. This is called __________.

Question 41

!( a > 3 ) is equivalent to:

A) a < 3.
B) a <= 3.
C) !a < 3.
D) !a <= 3.
E) !( a <= 3 ).

Question 42

!( a > 38 && b <= 67 ) is equivalent to:

A) a <= 38 && !b <= 67.
B) !a > 38 || !b <= 67.
C) !( a > 38 ) && !( b <= 67 ).
D) !( a > 38 ) || !( b <= 67 ).
E) a < 38 || b >= 67.

Question 43

If you have an if/else if/else code sequence with 4 blocks, what is the minimal number of input values that you should use to test your code?

A) 1
B) 2
C) 3
D) 4
E) 5

Question 44

The switch statement can be used instead of an if/else if statement:

A) at any time.
B) only when comparing the value of an expression to a floating point value.
C) only when comparing the value of an expression to any char or integer variable.
D) only when comparing the value of an expression to constant integers, characters, or Strings.
E) only when comparing the value of an expression to a constant String value.

Question 45

= is the equality operator.

Question 46

a && b is true only when both a and b are true.

Question 47

In an if statement, curly braces around the true block are mandatory.

Question 48

Inside an if statement, statements inside the true block must be indented, or the code will not compile.

Question 49

if statements can be nested.

Question 50

In else if, there is a space between else and if.

Question 51

a || b is true only when either a or b is true, but not when both a and b are true.

Question 52

&& and || have the same level of precedence.

Question 53

Inside the block of a switch statement, the break statements are optional.

Question 54

You cannot use a switch statement with Strings.

Question 55

Inside the block of a switch statement, the value of the expression is compared to the __________ constants in order.

Question 56

Inside the block of a switch statement, the keyword that plays the same role as else in an if or if/else if statement is __________.

Question 57

Before performing a division, it is a good idea to use an if statement to test if the value of the denominator is __________.

Question 58

When the data fall into two mutually exclusive categories, the appropriate structure to use is a(n) __________ statement.

Question 59

Name three String comparison methods.

Question 60

Convert the following if/else statement to one that uses the conditional operator:
if ( a % 2 == 0 )
System.out.println( "The number is even" );
else
System.out.println( "The number is odd" );

Question 61

What structure would you use if the data falls into five mutually exclusive categories, and how many blocks would you have?

Question 62

Assuming x, y, and z are int variables, evaluate what is wrong with the following expression: x < y && z

Question 63

Suppose that a true block is not skipped and curly braces are required. What can you infer about the condition and the number of statements in the true block?

Question 64

Why would if/else statements simplify processing?

Question 65

How would you organize nested if statements to specify which else clause pairs with which if statement?

Question 66

Contrast the equality operator with the Math.abs method to compute a difference between the two numbers and compare the difference to a threshold value.

Question 67

Explain why you would use equals( String str ).

Question 68

In what situation would you use the switch statement instead of an if/else if statement?