Question 1

As a rule of style, when writing an if statement you should indent the conditionally-executed statements.

Accepted Answer

It is a common convention and good practice to indent the statements that are executed conditionally within an if statement to improve readability and maintainability of the code. This helps to easily differentiate between the code that runs under the condition and the code that is executed regardless of whether the condition is met or not.

Question 2

If the expression on the left side of the following is true, the expression on the right side will not be checked.
(a > = b) || (c == d)

Accepted Answer

The statement is using the logical OR operator, which means that if the first expression (a >= b) is true, the second expression (c == d) will not be checked because the whole statement is already true. Therefore, the answer is A.

Question 3

Whereas < is called a relational operator, x < y is called a(n)

Accepted Answer

Although < is a type of operator, x < y is referred to as a relational expression because it compares the values of x and y and returns a Boolean result (true or false).

Question 4

The following code correctly determines whether x contains a value in the range of 0 through 100, inclusive.
if (x > 0 && <= 100)

Accepted Answer

The code is missing the variable name after the second comparison operator. It should be:

if (x > 0 && x <= 100)

Without the variable name, the code is invalid and will result in a compilation error.

Question 5

Relational operators allow you to __________ numbers.

Accepted Answer

Relational operators compare numbers to determine if they are equal, less than, greater than, less than or equal to, or greater than or equal to each other. They do not perform any mathematical operations such as addition or multiplication.

Question 6

The value of result in the following expression will be 0 if x has the value of 12.
result = x > 100 ?
 0 :
 1;

Accepted Answer

The expression checks if x is greater than 100. If it is, result will be 0, otherwise it will be 1. Since x is 12, which is definitely less than 100, the value of result will be 1.

Question 7

What is assigned to the variable result given the statement below with the following assumptions:
X = 10, y = 7, and x, result, and y are all int variables.
Result = x >= y;

Accepted Answer

In the statement, "result = x >= y", the ">=" operator compares x and y and returns a boolean value (either true or false). Then, this boolean value is assigned to the variable "result". Since x (10) is greater than or equal to y (7), the comparison evaluates to true, resulting in "result" being assigned the value of 1. Therefore, choice D is the correct answer.

Question 8

After the following code executes, what is the output if user enters 0? int x = -1; cout << "Enter a 0 or 1: "; cin >> x; if (c) $\quad$cout << "true" << endl; else $\quad$cout << "False" << endl;

Accepted Answer

If the user enters 0, the variable x will have the value 0. The condition in the if statement will therefore evaluate to false, and the code inside the else block will run. This code prints "False" to the console. Therefore, the output will be "False" if the user enters 0.

Question 9

You should be careful when using the equality operator to compare floating point values because of potential round-off errors.

Accepted Answer

Floating point values are imprecise and can have small round-off errors that can accumulate during operations. Therefore, directly comparing them using the equality operator can lead to unexpected results. It is recommended to use an epsilon value or a function that compares floating point values within a certain tolerance range.

Question 10

Both of the following if statements perform the same operation.
1. if (sales > 10000)
$\quad$$\quad$commissionRate = 0.15;
2. if (sales > 10000) commissionRate = 0.15;

Accepted Answer

Both statements perform the same operation of setting the commission rate to 0.15 if the sales are greater than 10000. The only difference is that the second statement does not have curly brackets {} to enclose the block of code to be executed if the condition is true. However, since there is only one statement to be executed in this case, the lack of curly brackets does not affect the behavior of the if statement.

Question 11

When a relational expression is False, it has the value

Accepted Answer

In programming languages, most relational expressions evaluate to either True (1) or False (0). This means that when a relational expression is False, it has the value of 0.

Question 12

An expression that has any value other than 0 is considered true by an if statement.

Accepted Answer

In Python, any non-zero value is considered True when evaluated in a boolean context, and therefore would satisfy the condition of an if statement. Only the integer value 0 and the boolean value False are considered False.

Question 13

The __________ is an equality (or comparison) operator.

Accepted Answer

The == operator is the only equality operator in the options provided. The >= operator is a greater than or equal to operator, the != operator is a not equal to operator, and the = operator is an assignment operator.

Question 14

The default section is required in a switch statement.

Accepted Answer

The default section in a switch statement is optional.

Question 15

The conditional operator takes two operands.

Accepted Answer

The conditional operator, also known as the ternary operator, takes three operands: a condition, a result upon true, and a result upon false.

Question 16

What is the output of the following code segment if the user enters 90 for the score? Cout << "Enter your test score: "; Cin >> test_score; If (test_score < 60) Cout << "You failed the test." << endl; If (test_score > 60) Cout << "You passed the test." Else Cout << "You need to study harder next time." << endl;

Accepted Answer

The code checks if the test_score is less than 60, which it isn't since the user entered 90. Then it checks if the test_score is greater than 60, which it is, so it outputs "You passed the test." The else statement is associated with the second if statement, but it doesn't execute because the condition for the if statement is true.

Question 17

If the expression on the left side of the following is False, the expression on the right side will not be checked.
(a > = b) && (c == d)

Accepted Answer

In logical AND operations, if the first condition is false, the second condition is not evaluated because the overall expression cannot be true.

Question 18

After the following code executes, what is the value of my_value if the user enters 0?
Cin >> my_value;
If (my_value > 5)
My_value = my_value + 5;
Else if (my_value > 2)
My_value = my_value + 10;
Else
My_value = my_value + 15;

Accepted Answer

Since the user enters 0, none of the conditions in the if-else if structure are met until the else block, which adds 15 to my_value, making it 15.

Question 19

If you place a semicolon after the statement:
If (x < y)

Accepted Answer

If a semicolon is placed after the statement "if (x < y)", the compiler will interpret it as a null statement and move on to the next line of code. This means that the if statement will not perform any action, but the code will still compile without any errors.

Question 20

What is the output of the following code segment?
Int x = 5;
If (x = 2)
Cout << "This is true!" << endl;
Else
Cout << "This is False!" << endl;
Cout << "That's all, folks!" << endl;

Accepted Answer

The code contains an assignment in the if condition (x = 2), which assigns 2 to x and evaluates to true. Therefore, "This is true!" is printed, followed by "That's all, folks!".

Quiz 4: Making Decisions

As a rule of style, when writing an if statement you should indent the conditionally-executed statements.

If the expression on the left side of the following is true, the expression on the right side will not be checked. (a > = b) || (c == d)

Whereas < is called a relational operator, x < y is called a(n)

The following code correctly determines whether x contains a value in the range of 0 through 100, inclusive. if (x > 0 && <= 100)

Relational operators allow you to __________ numbers.

The value of result in the following expression will be 0 if x has the value of 12. result = x > 100 ? 0 : 1;

What is assigned to the variable result given the statement below with the following assumptions: X = 10, y = 7, and x, result, and y are all int variables. Result = x >= y;

After the following code executes, what is the output if user enters 0? int x = -1; cout << "Enter a 0 or 1: "; cin >> x; if (c) $\quad$ cout << "true" << endl; else $\quad$ cout << "False" << endl;

You should be careful when using the equality operator to compare floating point values because of potential round-off errors.

Both of the following if statements perform the same operation. 1. if (sales > 10000) $\quad$ $\quad$ commissionRate = 0.15; 2. if (sales > 10000) commissionRate = 0.15;

When a relational expression is False, it has the value

An expression that has any value other than 0 is considered true by an if statement.

The __________ is an equality (or comparison) operator.

The default section is required in a switch statement.

The conditional operator takes two operands.

If the expression on the left side of the following is False, the expression on the right side will not be checked. (a > = b) && (c == d)

After the following code executes, what is the value of my_value if the user enters 0? Cin >> my_value; If (my_value > 5) My_value = my_value + 5; Else if (my_value > 2) My_value = my_value + 10; Else My_value = my_value + 15;

If you place a semicolon after the statement: If (x < y)

What is the output of the following code segment? Int x = 5; If (x = 2) Cout << "This is true!" << endl; Else Cout << "This is False!" << endl; Cout << "That's all, folks!" << endl;

Quiz 4: Making Decisions

As a rule of style, when writing an if statement you should indent the conditionally-executed statements.

If the expression on the left side of the following is true, the expression on the right side will not be checked. (a > = b) || (c == d)

Whereas < is called a relational operator, x < y is called a(n)

The following code correctly determines whether x contains a value in the range of 0 through 100, inclusive. if (x > 0 && <= 100)

Relational operators allow you to __________ numbers.

The value of result in the following expression will be 0 if x has the value of 12. result = x > 100 ? 0 : 1;

What is assigned to the variable result given the statement below with the following assumptions: X = 10, y = 7, and x, result, and y are all int variables. Result = x >= y;

After the following code executes, what is the output if user enters 0? int x = -1; cout << "Enter a 0 or 1: "; cin >> x; if (c) \quad cout << "true" << endl; else \quad cout << "False" << endl;

You should be careful when using the equality operator to compare floating point values because of potential round-off errors.

Both of the following if statements perform the same operation. 1. if (sales > 10000) \quad\quad commissionRate = 0.15; 2. if (sales > 10000) commissionRate = 0.15;

When a relational expression is False, it has the value

An expression that has any value other than 0 is considered true by an if statement.

The __________ is an equality (or comparison) operator.

The default section is required in a switch statement.

The conditional operator takes two operands.

If the expression on the left side of the following is False, the expression on the right side will not be checked. (a > = b) && (c == d)

After the following code executes, what is the value of my_value if the user enters 0? Cin >> my_value; If (my_value > 5) My_value = my_value + 5; Else if (my_value > 2) My_value = my_value + 10; Else My_value = my_value + 15;

If you place a semicolon after the statement: If (x < y)

What is the output of the following code segment? Int x = 5; If (x = 2) Cout << "This is true!" << endl; Else Cout << "This is False!" << endl; Cout << "That's all, folks!" << endl;

After the following code executes, what is the output if user enters 0? int x = -1; cout << "Enter a 0 or 1: "; cin >> x; if (c) $\quad$ cout << "true" << endl; else $\quad$ cout << "False" << endl;

Both of the following if statements perform the same operation. 1. if (sales > 10000) $\quad$ $\quad$ commissionRate = 0.15; 2. if (sales > 10000) commissionRate = 0.15;