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 = 1
if age >= 18:
print("You are an adult")
else:
print("You are a minor")
You are a minor
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:
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
a = random.randint(0, 100)
b = random.randint(0, 100)
print("a:", a)
print("b:", b)
if (a > b):
print("a > b")
elif (a == b):
print("a = b")
elif (a < b):
print("a < b")
a: 57
b: 60
a < 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
import random
letters = ['F', 'F', 'F', 'F', 'F', 'F', 'D', 'C', 'B', 'A', 'A']
# Function to ask a question and get a response
def question_with_response(prompt):
# Print the question
print("\033[91mQuestion: " + prompt)
# Get user input as the response
msg = input()
return msg
# Define the number of questions and initialize the correct answers counter
questions = 10
correct = 0
# Personalized greeting message
# Collect the student's name
user_name = input("Enter your name: ")
print('Hello, ' + user_name + " running " + sys.executable)
print("You will be asked " + str(questions) + " questions.")
answer = input("Are you ready to take a test?")
# Question 1: Boolean Basics
# Ask a question about Boolean values and check the response
# Provide feedback based on the correctness of the response
answer = question_with_response("\033[94mWhat is one Boolean Value?")
if (answer == "True" or answer == "False"):
print("Correct!")
correct += 1
answer = question_with_response("\033[94mWhat is the boolean for not true?")
if (answer == "False"):
print("Correct!")
correct += 1
# Question 2: Boolean Expressions
# Ask a question about Boolean expressions and their importance in programming
# Provide feedback based on the correctness of the response
answer = question_with_response("\033[94mWrite a Boolean Expression to represent variable 'grade' is True.")
if (answer == "grade == True" or answer == "grade==True"):
print("Correct!")
correct += 1
answer = question_with_response("\033[94mWrite a Boolean Expression to represent variable 'result' is not True.")
if (answer == "result != True" or answer == "result!=True"):
print("Correct!")
correct += 1
# Question 3: Conditional Statements
# Ask a question about the purpose of conditional (if-else) statements in programming
# Provide feedback based on the correctness of the response
answer = question_with_response("\033[94mWhat is a conditional keyword?")
if (answer == "if" or answer == "else"):
print("Correct!")
correct += 1
# Question 4: Relational Operators
# Ask a question about common relational operators in programming and provide examples
# Provide feedback based on the correctness of the response
answer = question_with_response("\033[94mWrite a Boolean Expression to represent variable 'mass' is greater than 5.")
if (answer == "mass > 5" or answer == "mass>5"):
print("Correct!")
correct += 1
answer = question_with_response("\033[94mWrite a Boolean Expression to represent variable 'score' is less or equal to 2.")
if (answer == "score <= 2" or answer == "score<=2"):
print("Correct!")
correct += 1
answer = question_with_response("\033[94mWrite a Conditional Statement to represent variable 'time' is greater or equal to variable 'distance'.")
if (answer == "time >= distance" or answer == "time>=distance"):
print("Correct!")
correct += 1
answer = question_with_response("\033[94mWrite a Conditional Statement to represent variable 'number' is not equal to variable 'speed'.")
if (answer == "number != speed" or answer == "number!=speed"):
print("Correct!")
correct += 1
# Question 5: Logical Operators
# Ask a question about the use of logical operators in programming and provide examples
# Provide feedback based on the correctness of the response
answer = question_with_response("\033[94mWhat is an example of a Logical Operator?")
if (answer == "and" or answer == "or" or answer == "not"):
print("Correct!")
correct += 1
random_score = random.randint(0, questions)
if (random_score > correct):
msg = "a lower score."
if (random_score < correct):
msg = "a higher score."
if (random_score == correct):
msg = "the same score."
# Display the final score
# Calculate the percentage of correct answers and provide feedback
print(f"\033[95mscore: {correct}/{questions} or {correct/questions*100}%") # correct / number of questions
print("\033[93mletter grade:", letters[int(correct/questions*10)])
print(f"\033[95mA random user scored {random_score}, and you got {msg}")
Enter your name: a
Hello, a running /usr/bin/python3
You will be asked 10 questions.
Are you ready to take a test? a
[91mQuestion: [94mWhat is one Boolean Value?
a
[91mQuestion: [94mWhat is the boolean for not true?
a
[91mQuestion: [94mWrite a Boolean Expression to represent variable 'grade' is True.
a
[91mQuestion: [94mWrite a Boolean Expression to represent variable 'result' is not True.
a
[91mQuestion: [94mWhat is a conditional keyword?
a
[91mQuestion: [94mWrite a Boolean Expression to represent variable 'mass' is greater than 5.
a
[91mQuestion: [94mWrite a Boolean Expression to represent variable 'score' is less or equal to 2.
a
[91mQuestion: [94mWrite a Conditional Statement to represent variable 'time' is greater or equal to variable 'distance'.
a
[91mQuestion: [94mWrite a Conditional Statement to represent variable 'number' is not equal to variable 'speed'.
a
[91mQuestion: [94mWhat is an example of a Logical Operator?
a
[95mscore: 0/10 or 0.0%
[93mletter grade: F
[95mA random user scored 5, and you got a lower score.