Question

State whether the following are true or false. If the answer is false , explain why. a. The default case is required in the switch selection statement. b. The break statement is required in the default case of a switch selection statement to exit the switch properly. c. The expression \((x>y 88 ay\) is true or the expression \(a

Short answer

a. False b. False c. True d. True

Step-by-step solution

Evaluate 'Default Case in Switch Statement'

The statement claims that a default case is required in a switch selection statement. In programming languages such as C and Java, the default case in a switch statement is optional. Therefore, this statement is false.

Evaluate 'Break Statement in Default Case'

The statement claims that a break statement is necessary in the default case to properly exit the switch. While a break statement is typically used to prevent fall-through in a switch case, including the default case, it is not strictly required. If omitted, control will pass to subsequent lines of code outside the switch. Therefore, this statement is false.

Analyze 'Expression Logical OR (||) Condition'

The expression \((x>y 88 ay)\ || \ (ay\) is true, \(a<b\) is true, or both. Therefore, this statement appears to be true assuming the two expressions separated by a logical OR.

Analyze 'Logical OR (||) with TRUE Operands'

The statement is correct in describing how the logical OR operator works. If either or both operands are TRUE, the entire expression evaluates to TRUE. Therefore, this statement is true.

Key concepts

Switch Statement

In C++, a switch statement is a control structure used for multi-way branching. This means it allows you to direct the flow of a program to different paths based on the value of a single variable or expression. The switch statement evaluates the expression inside its parentheses and compares it with a series of case labels. When it finds a match, it executes the code associated with that case label. This can be really helpful for replacing multiple if-else checks.

Here’s a simple illustration:

• A variable, for example, `int num`.
• The switch statement checks this variable's value against several cases: case 1, case 2, etc.
• When a case matches `num`, it executes the statements for that case.

The switch-case structure can simplify your code and make it easier to read, as long as the scenarios are discrete and based on integer or character comparisons.

Default Case

The default case in a switch statement is optional but useful. It provides a way to handle unexpected or unhandled values not explicitly covered by the case labels.

The default case acts like a safety net:

• If none of the case values match the expression, execution will jump to the default case if it is present.
• It usually appears at the end of the switch statement, although it can be positioned anywhere within the case labels.

Including a default case ensures that the switch statement doesn't just fall through with no action taken, which can help in debugging and managing errors. Despite its usefulness, it's not mandatory to include a default case, which gives programmers flexibility.

Logical Operators

Logical operators in C++ are tools that allow you to combine or modify boolean expressions. These operators include AND (`&&`), OR (`||`), and NOT (`!`).

Understanding the logical OR (`||`) operator is crucial:

• If either one or both of the operands are true, the result is true. For example, `(x > y) || (a < b)` yields true if `x > y` is true, `a < b` is true, or both.

Logical operators are powerful in decision-making processes within your code. They allow for efficient handling of complex conditional structures when you need to evaluate multiple criteria at once.

Break Statement

In a switch statement, a break statement is essential to control the flow of execution between cases. It prevents the phenomenon known as "fall-through," where the program runs the code for multiple cases without breaking in between.

Here’s why break statements are frequently used:

• When a case is matched and its statements run, coming across a break will exit the switch block immediately.
• If there is no break at the end of a case, execution continues to the next case and so on, until it finds a break or reaches the end of the switch block.

Although not required in every case, using a break statement ensures that only the matched case executes. In the case of a default, the break is also optional but often used to maintain control flow consistency.