Question 1

Using nested if statements without including braces to indicate the structure constitutes a common programming error.

Accepted Answer

When using nested if statements, it is important to use braces to indicate the structure of the code. Omitting the braces is a common programming error that can lead to unexpected results and hard-to-find bugs. Not including braces to indicate the structure of nested if statements can lead to errors in the code. It is a good practice to include braces to clearly define the structure and avoid errors.

Question 2

In C++, when comparing character data, the char values are coerced to ____ values automatically for the comparison.

Accepted Answer

When comparing character data, the char values are coerced to their corresponding integer values automatically for the comparison. Therefore, the best choice is D, which stands for int. When comparing character data, char values are automatically coerced to int values for the comparison. This happens because char data type is considered to be an integer data type with a 1-byte memory size, so comparing two char variables is essentially comparing two integers. Therefore, the best choice is D, which stands for int.

Question 3

In a relational expression, the value of the expression can be only the integer value 1 or ____.

Accepted Answer

In a relational expression, the value of the expression can be only the integer value 1 (true) or 0 (false), and neither -10 nor -1 nor 10 are valid possible results. Therefore, the correct answer is C, which represents the integer value 0. In a relational expression, the value can either be 1 or 0. 1 implies that the relation is true or valid, and 0 implies that the relation is false or invalid. The other options (-10, -1, 10) are not possible values for a relational expression.

Question 4

Before the current ANSI/ISO C++ standard, C++ didn t have a built-in Boolean data type with its two Boolean values, true and false .

Accepted Answer

Before the current ANSI/ISO C++ standard, C++ didn't have a built-in Boolean data type with its two Boolean values, true and false. This was added in the new standard. Before the current ANSI/ISO C++ standard, C++ did not have a built-in Boolean data type with its two Boolean values, true and false.

Question 5

The case keyword identifies the start of the switch statement.

Accepted Answer

The switch keyword identifies the start of the switch statement, not the case keyword. The case keyword specifies individual branches within the switch statement.

Question 6

A switch statement can contain any number of case labels in any order.

Accepted Answer

A switch statement can have any number of case labels in any order as long as they are of the same data type as the switch expression. A switch statement can have any number of case labels in any order as long as they are unique and constant expressions.

Question 7

A common problem with the if-else statement is using the assignment operator, = , in place of the relational operator == .

Accepted Answer

This is true because = is the assignment operator while == is the relational operator used to check for equality in conditions. Using = instead of == will assign a value to a variable instead of checking for equality in the condition. This is true as using the assignment operator instead of the relational operator in the if-else statement can lead to unexpected results and errors in the code. It is important to use == for comparison and = for assigning values to variables.

Question 8

Logical operators AND, OR, and NOT are represented by the symbols , ____, and !, respectively.

Accepted Answer

Logical AND operator is represented by '&&' in many programming languages, not '>>'. Logical OR operator is represented by '|' in some programming languages, but '||' is more common. Logical NOT operator is represented by '!' in most programming languages. Therefore, the best choice is B. The logical operator AND is represented by the symbol && in most programming languages, which is similar to the symbol || representing OR. As option B uses the symbol || for OR, it is the best choice. Option D uses the symbol | for OR, which can also represent a bitwise OR operator in some programming languages, but not a logical OR. Option A uses the symbol >> for right shift operator, and option C uses the symbol << for left shift operator, neither of which are logical operators.

Question 9

The switch statement requires you to terminate each case with a break statement.

Accepted Answer

While it's common to use a break statement to terminate each case in a switch statement, it's not required. Omitting the break statement will cause a "fall-through" to the next case, which can be intentional for certain logic flows.

Question 10

In C++, the postfix and prefix -- operators can be applied to Boolean variables.

Accepted Answer

The postfix and prefix -- operators can only be applied to variables that have numerical values, such as integers or floating-point numbers. They cannot be applied to Boolean variables. The -- operators can only be applied to numerical and pointer variables, not Boolean variables.

Question 11

In C++, strings of characters cannot be compared.

Accepted Answer

C++ allows for the comparison of strings using relational operators like ==, !=, <, >, <=, and >=. In C++, strings of characters can be compared using the comparison operators such as ==, >, <, >=, and <=.

Question 12

In C++, the logical ____ operator is used to change an expression to its opposite state.

Accepted Answer

The logical NOT operator is used to negate or invert the value of an expression. It returns a true value if the expression is false and vice versa. The NOT operator, represented by the exclamation mark (!), is used to invert the boolean value of an expression. For example, if a variable x is true, applying the NOT operator (!x) would result in false.

Question 13

Using the abs() function requires including the ____ header file.

Accepted Answer

The abs() function is defined in the cmath header file, therefore it must be included in order to use the function. The abs() function is used to obtain the absolute value of a number, and it is part of the cmath library. Therefore, including the cmath header file is necessary to use the abs() function.

Question 14

The ____ statement in C++ is used to implement a decision structure in its simplest form choosing between two alternatives.

Accepted Answer

The if-else statement is used to implement a decision structure in its simplest form choosing between two alternatives. The if-else statement in C++ allows for a simple decision structure where the program can choose between two alternatives based on a condition. The for and while statements are used for loops, and the switch-case statement is used for multiple conditional statements.

Question 15

The switch statement requires you to list the case values in increasing order.

Accepted Answer

The switch statement does not require case values to be listed in increasing order. It only requires that the case values be distinct and of the same data type as the switch expression. The order of case values does not matter in a switch statement.

Question 16

In C++, two string expressions can be compared by using relational operators or the ____ class s comparison methods.

Accepted Answer

C++ has a built-in string class that provides comparison methods such as ==, !=, <, >, etc. These can be used to compare two string expressions. Therefore, the best choice is A. The other options are not relevant for comparing string expressions in C++.

Question 17

The most commonly used ____ in if statements are simple relational expressions.

Accepted Answer

If statements require a condition to be evaluated in order to determine which branch of code to execute. The condition is typically a logical expression that evaluates to either true or false. These logical expressions are commonly referred to as "conditions", and they usually involve simple relational expressions (e.g. "x < y", "a == b", etc.). Comments and branches are not related to the evaluation of conditions in if statements. While "evaluation" could be seen as related to conditions, it does not make sense as an answer choice on its own. If statements rely on conditions to determine which branch of code to execute. The conditions are typically created using simple relational expressions such as < (less than), > (greater than), == (equal to), etc. Therefore, the most commonly used term in if statements is "conditions".

Question 18

A ____ relational expression consists of a relational operator that compares two operands.

Accepted Answer

A simple relational expression compares only two operands using a relational operator. A simple relational expression consists of a single relational operator that compares two operands.

Question 19

The condition used in an if statement can be any valid C++ expression.

Accepted Answer

Any valid C++ expression can be used as the condition in an if statement. The condition is evaluated as either true or false, and the body of the if statement is executed only if the condition is true. The condition in an if statement can be any expression that evaluates to a boolean value, i.e., true or false.

Question 20

One or more if-else statements can be included in either part of an if-else statement.

Accepted Answer

One or more if-else statements can be included within either the if block or the else block of the if-else statement. This is known as a nested if-else statement. One or more if-else statements, also known as nested if-else statements, can be included in either the "if" part or the "else" part of an if-else statement. This allows for more complex conditions and decision-making processes.

Quiz 4: Selection Structures