2.1.1 Common Data Types

Definitions, purpose, and Python examples

Integer
Definition: An integer is a whole number with no decimal point.

Purpose: Used for counting and quantities.

When used: When values cannot be fractional.

Python example:

age = 18
number_of_students = 25

print(age)
print(number_of_students)
        
Float
Definition: A float is a number that includes a decimal point.

Purpose: Used for precise measurements.

When used: When fractions or decimals are required.

Python example:

price = 9.99
temperature = 21.5

print(price)
print(temperature)
        
String
Definition: A string is a sequence of characters used to store text.

Purpose: Used for names, messages, and textual data.

When used: Whenever information is not numeric.

Python example:

name = "Alex"
message = "Welcome to Python"

print(name)
print(message)
        
Boolean
Definition: A Boolean stores one of two values: True or False.

Purpose: Used in decision‑making and conditions.

When used: When checking yes/no or true/false states.

Python example:

is_logged_in = True
has_permission = False

print(is_logged_in)
print(has_permission)