In this article, we will write a Python program to find the largest of three numbers using nested `if else`

statements. The program takes three numbers from the user as input, finds the largest among them and prints it on the output screen.

**Sample Example:**

Input: Enter first number: 20 Enter second number: 10 Enter third number: 30 Output: The largest number is: 30

To find out the largest of three numbers, there are two approaches that we generally use: First, using simple if…else statements and second using nested if…else statements.

Let’s say we have three numbers `a`

, `b`

& `c`

. To find out the largest of `a`

, `b`

& `c`

using the nested `if...else`

, we can use the following algorithm:

- Check if
`a`

is greater than`b`

:- If yes, either
`a`

or`c`

is the largest. - Check, if the
`a`

is also greater than`c`

, if yes,`a`

is the largest. - If not, the
`c`

is the largest.

- If yes, either
- If
`a`

is not greater than`b`

, this means:- Either
`b`

or`c`

is the largest. - Check if
`b`

is also greater than`c`

, if yes,`b`

is the largest. - If not,
`c`

is the largest.

- Either

Here is the implementation of the above algorithm in Python:

# Take the numbers from the user a = int(input('Enter first number: ')) b = int(input('Enter second number: ')) c = int(input('Enter third number: ')) # Find the largest among a, b & c if a > b: if a > c: largest = a else: largest = c else: if b > c: largest = b else: largest = c # Print the largest number print("The largest number is: ", largest)

**Output:**

Enter first number: 20 Enter second number: 100 Enter third number: 50 The largest number is: 100 Enter first number: -20 Enter second number: -10 Enter third number: -50 The largest number is: -10

This approach works for all positive and negative numbers including zero.