Programming · StudentHub Lesson

Conditionals

Learn how programs make decisions using if, elif, and else statements.

16 minBeginner

What you will learn

Write if, elif, and else statements in Python
Use comparison operators to build conditions
Combine conditions with and/or/not
Trace the flow of a conditional program
Avoid common conditional logic errors

Watch the lesson

Python for Beginners – Full Course [Programming Tutorial] · freeCodeCamp.org

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Topic notes

Main Idea

Conditionals let a program choose different actions depending on whether a condition is true or false.

Key Concepts

if runs code only when a condition is true
elif checks another condition if the first was false
else runs when none of the previous conditions were true
Comparison operators include ==, !=, >, <, >=, <=
Logical operators and/or/not combine multiple conditions

Definitions

Condition: an expression that evaluates to True or False
Comparison operator: symbols used to compare values
Logical operator: combines multiple boolean expressions

Syntax

```python

age = 16

if age >= 18:

print("Adult")

elif age >= 13:

print("Teenager")

else:

print("Child")

```

Examples

Checking if a number is even: if num % 2 == 0
Checking a password: if password == "1234"

Common Mistakes

Using = instead of == for comparison
Forgetting the colon at the end of if statements
Incorrect indentation of the code block

Key concepts

if/elif/else structureComparison operatorsLogical operatorsBoolean expressions

Important terms

Condition: An expression evaluating to True or False
elif: Keyword used to check another condition if the previous one was false

Worked examples

Problem

Write code to print 'Positive' or 'Negative' based on a number

1. num = -5
2. if num > 0: print('Positive')
3. else: print('Negative')

Answer: Negative

Quick revision

if runs when condition is True
elif checks additional conditions
else is the fallback case
== compares equality, = assigns values
Indentation defines code blocks in Python

Check your understanding

Question 1 · Multiple choice

Which operator checks if two values are equal in Python?

Question 2 · Multiple choice

What keyword runs code if none of the previous conditions were true?

Question 3 · True or false

You can have multiple elif statements in one if block.

Question 4 · Short answer

What will `if 5 > 3:` evaluate to?

Question 5 · Short answer

Fix this error: `if x = 5:`

Done with Conditionals?

Variables & Data Types Loops