2.4 Operators

Purpose: Perform mathematical calculations.

Examples include:

• Add (+)
• Subtract (-)
• Multiply (*)
• Divide (/)
• Exponentiation (**)
• Integer division (//)
• Modulus (%)

Python example:

a = 10
b = 3

print(a + b)
print(a - b)
print(a * b)
print(a / b)
print(a ** b)
print(a // b)
print(a % b)
        

Purpose: Compare values and return True or False.

Examples include:

• Equal to (==)
• Not equal to (!=)
• Less than (<)
• Greater than (>)
• Less than or equal to (<=)
• Greater than or equal to (>=)

Python example:

age = 18

print(age == 18)
print(age != 16)
print(age > 16)
print(age <= 21)
        

Purpose: Combine or invert conditions.

Examples include:

• and
• or
• not

Python example:

age = 20
has_id = True

print(age >= 18 and has_id)
print(age < 18 or has_id)
print(not has_id)
        

Interpreting code means understanding what the logic produces.

Python example:

numbers = [4, 6, 8]
total = numbers[0] + numbers[1]

print(total > numbers[2])
        

This checks whether the sum of the first two items is greater than the third.

Operators are used to create decision‑making logic.

Python example:

score = 70

if score >= 50:
    print("Pass")
else:
    print("Fail")
        

Debugging involves identifying incorrect logic or operators.

Incorrect code:

age = 18

if age = 18:
    print("Adult")
        

Problem: Assignment (=) used instead of comparison (==).

Corrected code:

if age == 18:
    print("Adult")