Class 11 Control Statements: if-else, if-elif-else, while loop, for loop

Control statements are fundamental programming concepts that allow you to control the flow of execution in your programs. In Class 11, understanding these concepts is crucial as they form the basis for decision-making and iterative processes in coding. Here’s a breakdown of each:

1. if-else Statement

The if-else statement allows you to execute a block of code if a condition is true and another block of code if the condition is false.

Syntax:

if condition:
    # Code to execute if the condition is true
else:
    # Code to execute if the condition is false

Example:

number = 10
if number > 5:
    print("The number is greater than 5.")
else:
    print("The number is 5 or less.")

2. if-elif-else Statement

The if-elif-else statement is an extension of the if-else statement. It allows you to check multiple conditions.

Syntax:

if condition1:
    # Code to execute if condition1 is true
elif condition2:
    # Code to execute if condition2 is true
else:
    # Code to execute if all conditions are false

Example:

number = 10
if number > 10:
    print("The number is greater than 10.")
elif number == 10:
    print("The number is exactly 10.")
else:
    print("The number is less than 10.")

3. while Loop

The while loop is used to execute a block of code repeatedly as long as a given condition is true.

Syntax:

while condition:
    # Code to execute repeatedly

Example:

count = 0
while count < 5:
    print("Count is:", count)
    count += 1

4. for Loop

The for loop is used to iterate over a sequence (like a list, tuple, dictionary, set, or string) and execute a block of code for each item in the sequence.

Syntax:

for variable in sequence:
    # Code to execute for each item in the sequence

Example:

python

for i in range(5):
    print("Iteration:", i)

In this example, range(5) generates numbers from 0 to 4, and the loop runs five times.

Summary

• if-else: Used for decision-making based on conditions.
• if-elif-else: Allows multiple conditions to be checked in sequence.
• while loop: Repeats code while a condition is true.
• for loop: Iterates over elements in a sequence.

Understanding these control statements will help you write programs that can make decisions and perform repeated tasks efficiently.