While Loop in Python

What is a While Loop?

A while loop repeatedly executes a block of code as long as a given condition remains True.

Syntax

while condition:
    # code block to repeat

Example

count = 1
while count <= 5:
    print(count)
    count += 1

How It Works

The loop checks the condition before each iteration. If the condition is True, the loop body runs. When the condition becomes False, the loop ends.

Additional Examples

# Example 1: Print even numbers up to 10
num = 2
while num <= 10:
    print(num)
    num += 2

# Example 2: Countdown from 5 to 1
count = 5
while count > 0:
    print(count)
    count -= 1
print("Blast off!")

# Example 3: Sum numbers until user inputs zero
total = 0
num = int(input("Enter a number (0 to stop): "))
while num != 0:
    total += num
    num = int(input("Enter a number (0 to stop): "))
print("Total sum:", total)

# Example 4: Infinite loop with break
while True:
    response = input("Type 'exit' to quit: ")
    if response == "exit":
        break
print("Exited the loop.")

# Example 5: Loop through list using index
fruits = ["apple", "banana", "cherry"]
i = 0
while i < len(fruits):
    print(fruits[i])
    i += 1