3.5 - 3.7 Notes
- Vocab
- What is a boolean?
- Boolean and Binary
- Must Knows
- Relational Operators in action
- The versatility of relational operators:
- Logical Operators!
- Lesson Overview: 3.6 - Conditionals
- Analyzing Code Walkthrough
Vocab
- boolean: a data type with two possible values - true or false
- logic operators: These types of operators don't necessarily deal with equivalent/non-equivalent values, but they rather work on operands to produce a singular boolean result
- selection: Selection determines which part of an algorithm are executed based on a condition being true or false
- algorithm: a finite set of instructions that accomplish a specific task
What is a boolean?
- A data type with two possible values: true or false
Boolean and Binary
So similar yet so different.
- Boolean math and binary notation both use the same two ciphers: 1 and 0.
- However, please note that Boolean quantities are restricted to a singlular bit (can only be either 1, or 0)
- On the otherhand, binary numbers may be composed of many bits adding up in place-weighted form to any finite value, or size
Must Knows
- A Boolean value is either TRUE or FALSE
- The AP Exam will provide you with a reference sheet with the operators below.
| Operators |
|---|
a = b |
a ≠ b |
a > b |
a < b |
a ≥ b |
a ≤ b |
- With the grades below, use a boolean expression to determine if the average grade is above an 80 and print the result (True or False)
- Try it in as few steps as possible!
- Be creative! There are obviously TONS of different practical solutions
grade1 = 90
grade2 = 65
grade3 = 60
grade4 = 75
grade5 = 95
sum = grade1 + grade2 + grade2 + grade3 + grade4 + grade5
avg = sum/5
print("The average grade is above 80:", avg > 80)
print("100 == 100:",100==100)
print("Hello == Adios:","greeting"=="farewell")
print("Hello != Adios:","greeting"!="farewell")
print("Hello == Hola:","greeting"=="greeting")
print("5>=4:", 5>=4)
print ('')
# Notice that relational operators can even work on lists!
# For lists, the relational operator compares each respective component until an answer is derived
print("['a','b','c'] > ['x','y','z']:", ['a','b','c'] > ['x','y','z'])
print("[1,2,3,5] > [1,2,3,4]:", [1,2,3,5] > [1,2,3,4])
print("[1,2,3,5] < [1,2,3,4]:", [1,2,3,5] < [1,2,3,4])
print("[1,2,3,5] == [1,2,3,4]:", [1,2,3,5] == [1,2,3,4]) # use == for if conditions
Logical Operators!
These types of operators don't necessarily deal with equivalent/non-equivalent values, but they rather work on operands to produce a singular boolean result
- AND : returns TRUE if the operands around it are TRUE
- OR : returns TRUE if at least one operand is TRUE
- NOT : returns TRUE if the following boolean is FALSE
print("1 > 2 or 5 < 12:", 1 > 2 or 5 < 12)
# Output TRUE using OR ^
# Output FALSE using NOT
print("24 > 8:", not 24 > 8)
# Output FALSE using AND
print("10 > 20:", 10 > 20 and False)
Conditional Statements
Also known as "if statements"
Can be seen as if statements or if blocks
- has an IF statement followed by a block statement
Can also be seen as if else statements or if else-blocks
- has an IF condition followed by a block statement
- has an ELSE condition followed by a second block statement
- the ELSE statement will only execute if the IF condition does not apply
x = 20
y = 10
if x > y:
print("x is greater than y")
x = 20
y = 10
if x > y:
print("x is greater than y")
else:
print("x is not greater than y")
num1 = 17
num2 = 118
sum = num1 + num2
if sum == 200:
print("200")
else:
print(str(sum))
- Nested conditional statements consist of conditional statements within other conditional statements
- Utilizes "if else" statements within "if else" statements
- Basics of a nested conditional:
-
Block Coding Visual of Nested Conditionals:
-
Example Psuedocode of Nested Conditional Statements
Analyzing Code Walkthrough
- Psuedocode to the left, block code to the right
-
Approach the problem by going through each condition one at a time
- Decide which ones are false to skip and which ones are true to execute
-
You Try:
score = 82
if (score >= 90)
{
console.log("You got an A, congrats!")
}
else;
{
if (score >= 75)
{
console.log("Please come to retake up to a 90 next week at tutorial!")
}
else
{
console.log("You have detention!")
}
}
The answer for the problem above: it should print "Please come to retake up to a 90 next week at tutorial!"
carbs = 36
protein = 25
sugar = 11
if (carbs >= 55 || protein <= 20 || sugar >= 15)
{
console.log("Your lunch is too unhealthy, please pick a new one")
}
else
{
if (carbs < 35 || protein < 25)
{
console.log ("This lunch is alright but try to add some more carbs or protein")
}
else
{
if (sugar >= 11)
{
console.log ("Looks great but lets see if we can cut down on sugar, we don't want diabetes!")
}
else
{
console.log ("Amazing, you created a healthy lunch!!!")
}
}
}
The answer for the problem above: It should print "Looks great but lets see if we can cut down on sugar, we don't want diabetes!"
Writing Nested Code Activity
- Write a program that fits these conditions using nested conditionals:
- If a person has at least 8 hours, they are experienced
- If a person is experienced their salary is 90k, if they have ten hours or above their salary 150k
- If a person is inexperienced their salary is always 50k
- print the salary of the person at the end and whether they are experienced or not
hours = 9 # if you use one equal sign, you are assigning a value to a variable; for the booleans, use 2 equal signs
if hours >= 10:
print("Very Experienced Person; Salary 150k")
else:
if hours >= 8:
print("Experienced Person; Salary 90k")
else:
print("Unexperienced Person; Salary 50k")