PD1: Chapter 4: Selections

• What is the Boolean datatype based on?

  Mathematics
• What does Boolean algebra describe?

  The mathematics of reasoning about true and false propositions
• What are the two values of the Boolean datatype?

  true and false
• How must Boolean values be written in C#?

  In lowercase
• How does the Boolean datatype in C# differ from C regarding truth values?

  In C#, numerical values cannot be used as Boolean values
• What is the keyword for the Boolean datatype in C#?

  bool
• How are Boolean values generated in C#?

  By comparing two numeric or char values using comparison operators
• What operator is used for equality testing in C#?

  ==
• What does the inequality operator != do in C#?

  Tests if two values are not equal
• Which operators are used for comparison in C#?

  <, <=, >, >=
• What is the result of the expression 3 < 2.7f in C#?

  false
• What does the expression 3 == 3.0f yield in C#?

  true
• Can comparison operators be used to compare String values in C#?

  No
• How can one compare String values in C#?

  Using the CompareTo method
• What does CompareTo return if the executing string is equal to the argument?

  0
• What does CompareTo return if the executing string is alphabetically less than the argument?

  A value less than zero
• What does CompareTo return if the executing string is alphabetically more than the argument?

  A value greater than zero
• Why can't CompareTo return a Boolean value?

  Because there are three possible outcomes
• What are the three Boolean operators in C#?

  not, and, or
• What does the not operator do in C#?

  It negates a Boolean value
• How is the and operator represented in C#?

  With two ampersands (&&)
• What is the behavior of the and operator (&&) in C#?

  It yields true if both operands are true
• What is the behavior of the or operator (||) in C#?

  It yields true if at least one operand is true
• What is a Boolean expression?


  An expression that yields a Boolean result
• What is an example of a Boolean expression?

  Testing for equality using the == operator
• What does the ternary conditional operator do?

  It takes three operands and returns one based on a Boolean condition
• When is the ternary conditional operator useful?

  To avoid writing an if-else statement
• What happens if the first operand of the ternary operator is true?

  The result is the second operand
• What happens if the first operand of the ternary operator is false?

  The result is the third operand
• What is the significance of the order of nested if statements?

  The outcome of the program changes if the order changes
• What does the switch command allow for in C#?

  Faster execution compared to nested if else statements
• What is the output of the DisplayMeasurement function when measurement is less than 0.0?

  "Measured value is {measurement}; too low."
• What is the output of the DisplayMeasurement function when measurement is greater than 15.0?

  "Measured value is {measurement}; too high."
• What is the output of the DisplayMeasurement function when measurement is NaN?

  "Failed measurement."
• What is the purpose of the break statement in a switch case?

  To exit the switch statement
• What does the case statement do in a switch?

  It defines a specific condition to match
• What is the syntax for a switch statement in C#?

  switch (expression) { case value: statement; }
• What is the role of the Console.WriteLine method in the DisplayMeasurement function?

  To output the measured value to the console

  
• What is the significance of the curly braces in an if statement?

  They define a block of code to be executed
• What does the else statement do in an if-else structure?

  It executes a block of code if the if condition is false