# How to use if else in python-Decision Making Statement

## Introduction

Welcome to the world of Python programming! One of the fundamental concepts every developer must grasp is making decisions based on conditions. We try to demystify the if-else statement in Python, explaining its syntax, use cases, and providing example programs to help you gain a solid foundation in this essential aspect of programming.

## What is an If-Else Statement?

The if-else statement is a powerful construct in Python that enables the execution of different code blocks based on specified conditions. It allows your program to make decisions and respond accordingly, resulting in dynamic and flexible code.

## Syntax of If-Else Statements in Python

The syntax of an if-else statement in Python is straightforward:

if condition:
# Code block executed if condition is True
else:
# Code block executed if condition is False

## When to Use If-Else Statements?

If-else statements are essential whenever you need your program to take different paths based on certain conditions. These conditions could be user input, data values, or any other logical expressions. If-else statements make your code more intelligent and responsive

## How to Use If-Else Statements?

To use if-else statements effectively, you need to define the conditions that determine which code block should be executed. The condition is an expression that evaluates to either True or False. If the condition is True, the code block following the `if` statement is executed. Otherwise, the code block following the `else` statement is executed.

## Example Programs

### Simple Temperature Converter:

temperature = float(input(“Enter the temperature in Celsius: “))
if temperature < 0:
print(“It’s freezing!”)
else:
print(“It’s not freezing!”)

### Greater of Two Numbers:

num1 = int(input(“Enter the first number: “))
num2 = int(input(“Enter the second number: “))

if num1 > num2:
print(“The first number is greater.”)
elif num2 > num1:
print(“The second number is greater.”)
else:
print(“Both numbers are equal.”)

### Voting Age:

age = int(input(“Enter your age: “))

if age >= 18:
print(“You are eligible to vote.”)
else:
print(“You are not eligible to vote yet.”)

### Positive or Negative Number:

num = int(input(“Enter a number: “))

if num > 0:
print(“The number is positive.”)
elif num < 0:
print(“The number is negative.”)
else:
print(“The number is zero.”)

### Odd or Even Number:

num = int(input(“Enter a number: “))

if num % 2 == 0:
print(“The number is even.”)
else:
print(“The number is odd.”)

These examples showcase how if-else statements can be used to make decisions based on conditions. They cover scenarios such as comparing numbers, determining voting eligibility, identifying positive or negative numbers, checking leap years, and distinguishing odd or even numbers.

Feel free to experiment with these programs and modify them according to your needs.

## Nested If-Else Statements

Nested if-else statements involve having an if-else statement inside another if or else block. This allows for multiple levels of conditions and decisions based on those conditions.

### Grade Calculator:

score = int(input(“Enter your score: “))
if score >= 90:
grade = ‘A’
elif score >= 80:
grade = ‘B’
elif score >= 70:
grade = ‘C’
else:
grade = ‘F’
print(“Your grade is:”, grade)

### Leap Year Check:

year = int(input(“Enter a year: “))

if year % 4 == 0:
if year % 100 == 0:
if year % 400 == 0:
print(“It’s a leap year.”)
else:
print(“It’s not a leap year.”)
else:
print(“It’s a leap year.”)
else:
print(“It’s not a leap year.”)

## Conclusion

In this blog, we explored the if-else statement in Python and its significance in decision-making. By understanding the syntax and use cases of if-else statements, you can make your code more dynamic and adaptive. Remember, the power of if-else statements lies in their ability to execute different code blocks based on conditions, making your programs smarter and more efficient.

By mastering the if-else statement and combining it with other programming concepts, you can create complex and robust applications that respond intelligently to various scenarios. Keep practicing, experimenting, and refining your skills, and you’ll soon be utilizing if-else statements with ease!

We hope you now have a solid foundation in understanding if-else statements in Python.

Happy coding!