Deck 4: Control Structures I: Selection

Question 1

Suppose x = 10 and y = 20. The value of the expression ((x >= 10) && (y is true.

Answer 1

True

Question 2

=! is a relational operator.

Answer 2

False

Question 3

In Java, !, &&, and || are called logical operators.

Answer 3

True

Question 4

Suppose P and Q are logical expressions. The logical expression P && Q is false if both P and Q are false.

Question 5

The expression 'A' 'B' evaluates to false while the expression 'A' 'B' evaluates to true.

Question 6

All switch cases include a break statement.

Question 7

When one control statement is located within another, it is said to be a controlled statement.

Question 8

Including a semicolon before the action statement in a one-way selection causes a syntax error.

Question 9

The symbol >= is a logical operator.

Question 10

In Java, case and switch are reserved words, but break is not a reserved word.

Question 11

A computer program will recognize both = and == as the equality operator.

Question 12

All switch structures include default cases.

Question 13

The expression !(x is true only if x is a positive number.

Question 14

Suppose that the input is 6 and console is a Scanner object initialized to the standard input device. Consider the following code.int alpha = 7;
int beta = console.nextInt();switch (beta)
{
case 5:
alpha = alpha + 1;
case 6:
alpha = alpha + 2;
case 7:
alpha = alpha + 3;
default:
alpha = alpha + 5;
}System.out.print(alpha);The output of this code is 9.

Question 15

A program uses selection to implement a branch.

Question 16

Suppose P and Q are logical expressions. The expression P || Q is true if both P and Q are true.

Question 17

Suppose that you have the following code.int num = 10;if (num > 10)
System.out.println(num);
else
System.out.println(num + 5);The output of this code is 5.

Question 18

Suppose that you have the following statements.int score;
String grade;if (score >= 65)
grade = "pass";
else
grade = "fail";If score is equal to 75, the value of grade is pass.

Question 19

The operators = and == have the same order of precedence.

Question 20

In Java, || has a higher precedence than &&.

Question 21

What is the output of the following Java code?int x = 0;
If (x > 0)
System.out.println("positive ");
System.out.println("zero ");
System.out.println("negative");

A) zero
B) negative
C) zero negative
D) positive zero negative

Question 22

Which of the following has the highest value?

A) '-'
B) '5'
C) 'H'
D) 'b'

Question 23

'A' = 7 || 4 Based on the code above, which part of the expression is not evaluated?

A) 2.5 >= 7
B) 4
C) 2.5 >= 7 || 4
D) 4

Question 24

Which of the following will cause a syntax error, if you are trying to compare x to 5?

A) if (x == 5)
B) if (x = 5)
C) if (x<= 5)
D) if (x >= 5)

Question 25

In a ____ control structure, the computer executes particular statements depending on some condition(s).

A) looping
B) repetition
C) selection
D) sequence

Question 26

Two-way selection in Java is implemented using ____.

A) if statements
B) for loops
C) if...else statements
D) sequential statements

Question 27

Which of the following is NOT a relational operator in Java?

A)< >
B)<
C) ==
D) >

Question 28

The method compareTo is part of the class String.

Question 29

What does >= mean?

A) less than
B) greater than
C) less than or equal to
D) greater than or equal to

Question 30

Suppose that x is an int variable. Which of the following expressions always evaluates to false?

A) (x > 0) || (x<=0)
B) (x > 0) || (x == 0)
C) (x > 0) && ( x<=0)
D) (x >= 0) && (x == 0)

Question 31

Which of the following is a relational operator?

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

Question 32

Suppose that you have the following statements.String str1 = "cat";
String str2 = "cats";The statement str1.equals(str2); is true.

Question 33

The execution of a break statement in a switch statement terminates the switch statement.

Question 34

Which of the following is not a logical operator?

A) !
B) ||
C) !=
D) &&

Question 35

Which of the following will cause a syntax error?

A) (10 < num) && (num < 30)
B) 10 < num <20
C) 10 < num && num < 25
D) num > 10 && num<40

Question 36

Suppose str1 and str2 are String variables. The expression (str1 == str2) determines whether str1 and str2 point to the same String object.

Question 37

int x, y;if (x 4)
{
If (x > 7)
Y = 4;
Else
Y = 6;
}
Else
Y = 8;Based on the code above, what is the value of y if x = 4?

A) 2
B) 4
C) 6
D) 8

Question 38

The output of the Java code:int alpha = 5;
int beta = 4;switch (beta)
{
case 2:
alpha = alpha + 2;
case 4:
alpha = alpha + 4;
break;
case 6:
alpha = alpha + 6;
default:
alpha = alpha + 10;
}
System.out.print(alpha);is: 9

Question 39

After the execution of the following code, what will be the value of num if the input values are 0 3? (Assume that console is a Scanner object initialized to the standard input device.)int num = console.nextInt();if (num > 0)
Num = num + 13;
Else
If (num >= 3)
Num = num + 15;

A) 0
B) 3
C) 13
D) 15

Question 40

'A' = 7 || 4 What is the value of the expression above?

A) true
B) false
C) x
D) It cannot be determined.

Question 41

int x;
X = (1 'K' >= 'F') ? 5 : 12Based on the code above, what is the value of x?

A) 1
B) 3
C) 5
D) 12

Question 42

int x, y;if (x 4)
{
If (x > 7)
Y = 4;
Else
Y = 6;
}
Else
Y = 8;Based on the code above, what is the value of y if x = 9?

A) 2
B) 4
C) 6
D) 8

Question 43

The conditional operator ?: takes ____ arguments.

A) two
B) three
C) four
D) five

Question 44

switch (lastInitial)
{
Case 'A':
System.out.println("section 1");
Break;
Case 'B':
System.out.println("section 2");
Break;
Case 'C':
System.out.println("section 3");
Break;
Case 'D':
System.out.println("section 4");
Break;
Default:
System.out.println("section 5");
}Based on the code above, what is the output if lastInitial = 'E'?

A) section 2
B) section 3
C) section 4
D) section 5

Question 45

Suppose that you have the following code:int sum = 0;
Int num = 8;if (num 5)
Sum = num + 15;After this code executes, what is the value of sum?

A) 0
B) 8
C) 15
D) 23

Question 46

int x, y;if (x 4)
{
If (x > 7)
Y = 4;
Else
Y = 6;
}
Else
Y = 8;Based on the code above, what is the value of y if x = 5?

A) 2
B) 4
C) 6
D) 8

Question 47

switch (lastInitial)
{
Case 'A':
System.out.println("section 1");
Break;
Case 'B':
System.out.println("section 2");
Break;
Case 'C':
System.out.println("section 3");
Break;
Case 'D':
System.out.println("section 4");
Break;
Default:
System.out.println("section 5");
}Based on the code above, what is the output if lastInitial = 'C'?

A) section 1
B) section 2
C) section 3
D) section 5

Question 48

If str1 is "Hello" and str2 is "Hi", which of the following could not be a result of str1.compareTo(str2);?

A) -9
B) -5
C) -1
D) 1

Question 49

int x, y;if (x 4)
{
If (x > 7)
Y = 4;
Else
Y = 6;
}
Else
Y = 8;Based on the code above, what is the value of y if x = 1?

A) 2
B) 4
C) 6
D) 8

Question 50

What is the output of the following Java code?int x = 57;
Int y = 3;switch (x % 9)
{
Case 0:
Case 1:
Y++;
Case 2:
Y = y - 2;
Break;
Case 3:
Y = y + 2;
Case 4:
Break;
Case 5:
Case 6:
Y = y + 3;
}System.out.println(y);

A) 2
B) 5
C) 6
D) 57