What is the "elif" statement in Python and how to use it?
Table of Contants
Introduction:
The elif
statement in Python stands for "else if" and is used to add multiple conditions to an if-else
structure. It allows your program to evaluate a sequence of conditions, executing the first block of code where the condition is True
. If none of the if
or elif
conditions are True
, the else
block (if present) is executed. The elif
statement helps you handle complex logic with multiple decision points in a clean and readable way.
Syntax and Basic Usage of the elif
Statement
The structure of an if
-elif
-else
block looks like this:
if
: Checks the first condition.elif
: Checks another condition if the previousif
(orelif
) condition isFalse
.else
: A final block that runs if none of the conditions areTrue
.
Example:
- In this example, if
age
is less than 18, the program prints "You are a minor." If it's between 18 and 64, it prints "You are an adult." Otherwise, it prints "You are a senior citizen."
How the elif
Statement Works
- The
if
condition is evaluated first. - If the
if
condition isTrue
, the corresponding block of code is executed, and the rest of theelif
andelse
blocks are skipped. - If the
if
condition isFalse
, the program evaluates the firstelif
condition. - This process continues for each
elif
condition until aTrue
condition is found or all conditions have been evaluated. - If none of the conditions are
True
, theelse
block is executed.
Example: Multiple Conditions Using elif
- Here, the program checks each condition in sequence. Since
score
is 75, the conditionscore >= 70
isTrue
, so it prints "Grade: C" and skips the rest of the conditions.
When to Use elif
You should use elif
when you need to check multiple conditions and want to avoid nested if
statements, which can make your code less readable. The elif
structure is a cleaner and more efficient way to handle multiple decision points.
Example: Checking Multiple Categories
- In this example, the program evaluates each condition. Since
temperature
is 30, the output is "It's warm."
Combining elif
with Logical Operators
You can also combine conditions in the elif
block using logical operators like and
, or
, and not
to create more complex conditions.
Example:
- In this example, multiple conditions are combined using the
and
operator in theelif
block to differentiate between morning and afternoon on Sunday.
Practical Examples of Using elif
1. Using elif
in Age Verification:
2. Handling Multiple Conditions with elif
:
3. Grading System Using elif
:
Conclusion:
The elif
statement in Python is a versatile tool for handling multiple conditions in your programs. It works seamlessly with if
and else
to create efficient, readable decision-making structures. By using elif
, you can avoid deeply nested if
statements and write clean, easy-to-understand code. Whether you are building complex decision trees or handling simple conditional logic, the elif
statement provides a powerful way to control the flow of your program.