If Else Program in Python

Last Updated on January 30, 2024 by Ankit Kochar

Programming languages provide various constructs to control the flow of execution based on certain conditions. One such essential construct in Python is the "if-else" statement. The "if-else" statement allows you to make decisions in your code by evaluating conditions and executing different blocks of code based on whether the conditions are true or false.
In Python, the "if-else" statement is part of the broader family of conditional statements, providing a flexible way to create logic branches within your programs. This construct enables you to write code that adapts to different scenarios, making your programs more dynamic and responsive to different inputs or conditions. In this guide, we will explore the syntax and usage of the "if-else" statement in Python, understand how it facilitates decision-making in your code, and provide examples to illustrate its application in real-world scenarios.

What is If Statement?

A control structure in Python executes a block of code if a condition is true.

Algorithm for if Statement

Here’s the algorithm for the if statement in Python:

• Evaluate the expression inside the if statement.
• If the expression is True, execute the block of code inside the if statement.
• If the expression is False, skip the block of code inside the if statement and continue with the next statement after the if block.

Example if Statement

x = 10

if x > 5:
    print("x is greater than 5")

The If Else Statement

A control structure in Python executes a block of code if a condition is true, and another block of code if the condition is false.

Algorithm for if-else Statement

Here’s the algorithm for the if-else statement in Python:

• Evaluate the expression inside the if statement.
• If the expression is True, execute the block of code inside the if statement.
• If the expression is False, execute the block of code inside the else statement.
• Continue with the next statement after the if-else block.

Example of if else Program in Python

x = 10

if x > 5:
    print("x is greater than 5")
else:
    print("x is smaller than or equal to 5")

The Elif Statement

A control structure in Python that allows you to test multiple conditions and execute a block of code if any of the conditions is true.

Algorithm for elif Statement in Python

Here’s the algorithm for the elif statement in Python:

• Evaluate the expression inside the if statement.
• If the expression is True, execute the block of code inside the if statement.
• If the expression is False, evaluate the next expression inside the elif statement.
• If the expression in any of the elif statements is True, execute the block of code inside that elif statement.
• If all expressions are False, execute the block of code inside the else statement (if there is one) or continue with the next statement after the if-elif block.

Example Program elif Statement in Python

num = 10

if num < 0:
    print("Number is negative")
elif num == 0:
    print("Number is zero")
else:
    print("Number is positive")

Conclusion
The "if-else" statement is a fundamental building block in Python programming, providing a powerful mechanism for making decisions within your code. By evaluating conditions and executing different code blocks based on those conditions, you can create versatile and adaptive programs. Whether handling user inputs, processing data, or responding to dynamic scenarios, mastering the use of "if-else" statements is essential for any Python developer. Through this guide, we hope you have gained a solid understanding of how to use "if-else" statements effectively in your Python programs.

Frequently Asked Questions(FAQs) Related to If Else Program in Python

Here are some FAQs related to the If Else Program in Python.

1. How does short-circuiting work in Python's "if-else" statements?
Python uses short-circuit evaluation. In an "or" condition, if the first part is true, the second part is not evaluated. In an "and" condition, if the first part is false, the second part is not evaluated.

2. Can I have multiple "elif" (else if) statements in Python?
Yes, you can use multiple "elif" statements between the "if" and "else" blocks to check for additional conditions. This allows you to create more complex decision trees.

3. How are conditions evaluated in the "if-else" statement?
The condition in the "if" statement is evaluated. If it is true, the code inside the "if" block is executed. If the condition is false, the code inside the "else" block (if present) is executed.

4. Can I nest "if-else" statements in Python?
Yes, you can nest "if-else" statements by placing one inside another. However, it's essential to maintain proper indentation for readability.

5. What happens if there is no "else" block?
If there is no "else" block, and the condition in the "if" statement is false, the program simply skips the "if" block and continues with the subsequent code.