Lesson 3.1: Conditional Statements (if, else, elif)
Introduction:
Conditional statements allow a program to make decisions and execute different blocks of code based on certain conditions. In Python, if, else, and elif are used to implement decision-making logic. Mastering these statements is essential for building dynamic and responsive programs.
1. The if Statement:
-
Executes a block of code only if the condition is
True.
Syntax:
Example:
2. The else Statement:
-
Executes a block of code when the
ifcondition isFalse.
Syntax:
Example:
3. The elif Statement:
-
Stands for “else if” and allows multiple conditions to be checked sequentially.
Syntax:
Example:
Practical Tips:
-
Use proper indentation for all blocks under
if,elif, andelse. -
Conditions are evaluated from top to bottom; the first true condition executes its block.
-
Combine multiple conditions using logical operators (
and,or,not).
Learning Outcome of This Lesson:
-
Understand and apply
if,else, andelifstatements -
Write programs that make decisions based on conditions
-
Use multiple conditions and logical operators for complex decision-making
-
Build dynamic programs that respond differently to various inputs
