Boolean

  • A Boolean value is either true or false.
  • A Boolean expression produces a Boolean value (true or false) when evaluated.

Conditional ("if") statements

  • Affect the sequential flow of control by executing different statements based on the value of a Boolean expression.
IF (condition)
{
	<block of statements>
}

The code in <block of statements> is executed if the Boolean expression condition evaluates to true; no action is taken if condition evaluates to false.

IF (condition)
{
	<block of statements>
}
ELSE
{
	<second block of statements>
}

The code in the first <block of statements> is executed if the Boolean expression condition evaluates to true; otherwise, the code in <second block of statements> is executed.

Example: Calculate the sum of 2 numbers. If the sum is greater than 10, display 10; otherwise, display the sum.

num1 = INPUT
num2 = INPUT
sum = num1 + num2
IF (sum > 10)
{
	DISPLAY (10)
}
ELSE
{
	DISPLAY (sum)
}

Hack 1

  • Add a variable that represents an age.

  • Add an ‘if’ and ‘print’ function that says “You are an adult” if your age is greater than or equal to 18.

  • Make a function that prints “You are a minor” with the else function.

## YOUR CODE HERE
age = 18

if age >= 18:
    print('You are an adult')
else:
    print('You are a minor')

You are an adult

Relational operators:

  • Used to test the relationship between 2 variables, expressions, or values. These relational operators are used for comparisons and they evaluate to a Boolean value (true or false).

Ex. a == b evaluates to true if a and b are equal, otherwise evaluates to false

  • a == b (equals)
  • a != b (not equal to)
  • a > b (greater than)
  • a < b (less than)
  • a >= b (greater than or equal to)
  • a <= b (less than or equal to)

Example: The legal age to work in California is 14 years old. How would we write a Boolean expression to check if someone is at least 14 years old?

age >= 14

Example: Write a Boolean expression to check if the average of height1, height2, and height3 is at least 65 inches.

(height1 + height2 + height3) / 3 >= 65

Hack 2

  • Make a variable called ‘is_raining’ and set it to ‘True”.

  • Make an if statement that prints “Bring an umbrella!” if it is true

  • Make an else statement that says “The weather is clear”.

## YOUR CODE HERE
is_raining = True

if is_raining is True: 
    print("Bring an umbrella!")
else:
    print("The weather is clear")

Bring an umbrella!

Logical operators:

Used to evaluate multiple conditions to produce a single Boolean value.

  • NOT evaluates to true if condition is false, otherwise evaluates to false
  • AND evaluates to true if both conditions are true, otherwise evaluates to false
  • OR evaluates to true if either condition is true or if both conditions are true, otherwise evaluates to false

Example: You win the game if you score at least 10 points and have 5 lives left or if you score at least 50 points and have more than 0 lives left. Write the Boolean expression for this scenario.

(score >= 10 AND lives == 5) OR (score == 50 AND lives > 0)

Relational and logical operators:

Example: These expressions are all different but will produce the same result.

  • age >= 16
  • age > 16 OR age == 16
  • NOT age < 16

Hack 3

  • Make a function to randomize numbers between 0 and 100 to be assigned to variables a and b using random.randint

  • Print the values of the variables

  • Print the relationship of the variables; a is more than, same as, or less than b

## YOUR CODE HERE
import random
variable_a = random.randrange [0,100]
variable_b = random.randrange [0,100]

if variable_a > variable_b:
    print("variable a is larger than variable b")
elif variable_b > variable_a:
    print("variable b is greater than variable b")
else:
    print("variable a is equal to variable b")

Homework

Criteria for above 90%:

  • Add more questions relating to Boolean rather than only one per topic (ideas: expand on conditional statements, relational/logical operators)
  • Add a way to organize the user scores (possibly some kind of leaderboard, keep track of high score vs. current score, etc. Get creative!)
  • Remember to test your code to make sure it functions correctly.
#HOMEWORK


# The quiz contains questions related to Boolean values, Boolean expressions,
# conditional statements, relational operators, and logical operators.

# Import necessary modules
import getpass  # Module to get the user's name
import sys  # Module to access system-related information

# Function to ask a question and get a response
def question_with_response(prompt):
    # Print the question
    print("Question: " + prompt)
    # Get user input as the response
    msg = input()
    return msg

# Define the number of questions and initialize the correct answers counter
questions = 5
correct = 0
user_name=input()
# Question 1: Boolean Basics 
response = question_with_response("What are the possible values of a Boolean variable?")
if response.lower() == "true or false":
    print("Correct!")
    correct += 1
else:
    print("Incorrect.")

# Question 2: Boolean Expressions
response = question_with_response("Why are Boolean expressions important in programming?")
if "control flow" in response.lower() and "decision making" in response.lower():
    print("Correct!")
    correct += 1
else:
    print("Incorrect.")

# Question 3: Conditional Statements
response = question_with_response("What is the purpose of conditional (if-else) statements in programming?")
if "execute different code" in response.lower() and "conditions met" in response.lower():
    print("Correct!")
    correct += 1
else:
    print("Incorrect.")

# Question 4: Relational Operators
response = question_with_response("Give an example of a relational operator in programming.")
if response.lower() == "==" or response.lower() == "<=" or response.lower() == ">=":
    print("Correct!")
    correct += 1
else:
    print("Incorrect.")

# Question 5: Logical Operators
response = question_with_response("Provide an example of a logical operator in programming.")
if response.lower() == "and" or response.lower() == "or" or response.lower() == "not":
    print("Correct!")
    correct += 1
else:
    print("Incorrect.")

# Display the final score
percentage_correct = (correct / questions) * 100
print(user_name + ", you scored " + str(correct) + "/" + str(questions) + " which is " + str(percentage_correct) + "%.")


Question: What are the possible values of a Boolean variable?
Correct!
Question: Why are Boolean expressions important in programming?
Incorrect.
Question: What is the purpose of conditional (if-else) statements in programming?
Incorrect.
Question: Give an example of a relational operator in programming.
Correct!
Question: Provide an example of a logical operator in programming.
Correct!
, you scored 3/5 which is 60.0%.