Nested-if statement in Python Programming

Nested-if Statement in Python: Nested-if statement is also the most important and easiest concept of control flow statements. This statement is very helpful, while or when we need to make a decision (when we have more than one condition to check) based on our problem.

A nested if is a flow control statement that’s the target of another if-statement. By nested-if statements, we mean to use an if-statement inside another if-statement. In Python, it is possible to place one if-statement inside the other if-statement.

We will learn about these flow control statements in detail.

Also, there are other control statements, These are given below:-

if (already discussed)
if-else (already discussed)
if-elif (already discussed)
if-elif-else (already discussed)
nested-if

Let’s discuss all above statements in detail one by one:- If, if-else statements,if-elif, and if-elif-else we have discussed already, followed by this article (if-statement, if-else statement,if-elif,if-elif-else), now we discuss nested-if:

nested-if-statement-in-python

(i). Nested-if statement: The nested-if statement’s execution is different from our previous control statements that we have discussed so far. The nested-if statement can be used inside the other if statement. This flow control statement is very helpful when we have to deal with a large number of conditions.

Syntax:

#nested-if statement example

x = 21
if(x==21):         #first if
    if(x > 20):     #second if 
    print(x)

# output
# 21

The above given example is the easiest example to understand the nested-if statement.

Note: Here we can also use anything else at the last. If both of the conditions inside if-statements remain false, then the statement inside else: block will execute. Below the given example of a nested if-else statement in python:

Example 1: Example of nested if-else statement in python.

#nested-if statement example 

x = 18 
if(x==23):
   print(x) 
   if(x==22):
   print(x)
   else: 
   print("Inside Else Block")
else:
   print("Condition get False, Hence it didn't enter if condition")

# output
# Condition get False, Hence it didn't enter if condition

Explanation:

In this example, we’re dealing with multiple if statements i.e. nested-if statements.
We are only allowed to enter the if statement, if the condition is True else we directly jump to the elif or else statement block.
Here in this example, our condition is false as it is checking for the value of x is equal to 23 which is not True. The value of x was 18.
And also there is no, elif block hence the flow control is directly jumped to else block and the result is returned as ‘Condition get False, Hence it didn’t enter if condition’.

Example 2: Write a program to display the greatest among three numbers using nested if statement.

a = 40
b = 80
c = 70

if(a>b):
    if(a>c):
    print("a is greater")

if(b>a):
    if(b>c):
    print("b is greatest")

if(c>a):
    if(c>b):
    print("c is greatest")

# output
# b is greatest

Explanation:

Here in this example, we are checking the greatest among three numbers using nested if condition.
We have a, b and c with initialised value 40, 80 and 70 respectively.
To compare each variable value we are using a nested if control statement.
Our approach is that suppose number a is greater than b means to be greatest it should also be greater than c hence we are checking both by using another if condition.
Hence the final output is obtained.
The best approach to find the greatest amount three number is the if-elif-else statement.

Other Control Flow Statements: