Lec6: Intro to Branching + If statements

Question 1

A boolean expression is one that is either:

Answer 1

true or false

Question 2

This type of operator determines whether a specific relationship exists between two values:

Answer 2

Relational

Question 3

Which of the following expressions will determine whether x is less than or equal to y?

Answer 3

x <= y

Question 4

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;

Answer 4

15

Question 5

What will be the value of ans after the following code has been executed?

int ans = 10;
int x = 65;
int y = 55;
if (x >= y)
ans = x + y;

Answer 5

120

Question 6

A block of code is enclosed in a set of:

Answer 6

braces { }

Question 7

What will be the value of ans, x and y after the following statements are executed?

int ans = 35, x = 50, y = 50;
if x >= y)
{
ans = x + 10;
x -= y;
}
else
{
ans = y + 10;
y += x;
}

Answer 7

ans = 60, x = 0, y = 50

Question 8

The expression tested by an if statement must evaluate to:

Answer 8

true or false

Question 9

If you prematurely terminate an if statement with a semicolon, the compiler will:

Answer 9

Assume you are placing a null statement there

Not display an error message (all of the above)

Question 10

What is the value of x after the following code has been executed?

int x = 75;
int y = 90;
if (x != y)
x += y;

Answer 10

165

Question 11

What is the value of ans after the following code has been executed?

int x = 40;
int y = 40;
int ans = 0;
if (x = y)
ans = x + 10;

Answer 11

No value, this is a syntax error.

Question 12

What is the value of ans after the following code has been executed?

int x = 35;
int y = 20, ans = 80;
if (x < y);
ans += y;

Answer 12

80

Question 13

An important style rule you should follow when writing if statements is to line up the conditionally executed statement with the if statement.

Answer 13

False

Question 14

Unicode is an international encoding system that is extensive enough to represent ALL the characters of ALL the world’s alphabets.

Answer 14

True

Question 15

What would be the output generated to the screen upon running the code fragment?

int a = 8, b = 10;
if (b < a)
if (a + 2 >= b)
System.out.println(“Joe);
else
System.out.println(“Jane”);
else
if (a + 2 <= b)
System.out.println(“John”);

Answer 15

John

Question 16

Java’s if statement executes the statement inside its body if a specific _____ is ______.

Answer 16

condition, true

Question 17

Which statement is false:

A. If the condition in an if statement is met, the statement in the body of the if statement is executed.
B. The equality operators have a higher level of precedence than the relational operators.
C. Executable Java statements either perform actions or make decisions.
D. All the relational operators have the same level of precedence.

Answer 17

B. The equality operators have a higher level of precedence than the relational operators.

Question 18

Structured design advocates the use of software modules. Which of the following items are advantages of this approach?

modules are easier to modify
all of the above
modules can be reused
modules cost less to develop

Answer 18

All of the above

Question 19

Which of the following is not a restriction of structured programming?

Answer 19

Each module has nested modules

Question 20

In structured programming’s _____ structure, the logic flow branches depending on certain conditions being met.

Answer 20

Decision

Question 21

What will be the value of the variable coupons after running the code fragment?

int books = 2, coupons;

if (books < 1)
coupons = 0;
else if (books < 3)
coupons = 1;
else if (books < 5)
coupons = 2;
else
coupons = 3;

Answer 21

1

Question 22

What will be printed after running the code fragment?

int y = 0, x = 2;

if (x <= 1)
y = 3;
if (x <= 2)
y = 5;
if (x == 3)
y = 7;
else
y = 9;

System.out.println ( y );

Answer 22

9

Question 23

Which of the following is typically used in a flowchart to indicate a decision?

Answer 23

Diamond

Question 24

In Java, the value of (4 > 7) is _____.

Answer 24

False

Question 25

Two truths and a lie: Two of the following statements are true, and one of them is FALSE. Identify the FALSE statement.

A. Pseudocode and flowcharts are both tools that are used to check the syntax of computer programs.
B. In a decision structure, alternative courses of action are chosen based on a Boolean value.
C. In a sequence structure, one step follows another unconditionally.

Answer 25

A. Pseudocode and flowcharts are both tools that are used to check the syntax of computer programs.

Question 26

What will be the boolean expression needed in order to check if the value is an odd number or not? In other words, what boolean expression is the appropriate choice to fill in the blank?

int value = 11;

if (_______________)
System.out.println(“The value is an odd number.”);
else
System.out.println(“The value is an even number.”);

Answer 26

x % 2 == 1

Question 27

Which of the following statements is true.

1. for every ‘if’ there should be an ‘else’.
2. for every ‘else’ there should be an ‘if’.
3. ‘if’ block can exist without an ‘else’
4. ‘if’ condition can be used inside another ‘if’ condition.

Answer 27

Only 2, 3, and 4 are true.