How to write a while loop that prints even numbers from 1 to 10 in Python

Introduction

In this Python tutorial, we will explore how to write a while loop that prints even numbers from 1 to 10. While loops are a fundamental control structure in programming, and understanding how to use them effectively is crucial for any Python developer. By the end of this guide, you'll have a solid grasp of how to implement a while loop to achieve this task.

Skills Graph

Understanding While Loops

In Python, a while loop is a control flow statement that repeatedly executes a block of code as long as a given condition is true. The basic syntax of a while loop is:

while condition:
    ## code block

The condition is a boolean expression that is evaluated before each iteration of the loop. If the condition is True, the code block inside the loop is executed. This process continues until the condition becomes False.

while loops are useful when you don't know in advance how many times the loop needs to run. They allow you to repeat a set of instructions until a specific condition is met.

Here's an example of a while loop that prints the numbers from 1 to 5:

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

This loop will continue to execute as long as the count variable is less than or equal to 5. In each iteration, the current value of count is printed, and then the count variable is incremented by 1.

It's important to ensure that the condition in a while loop will eventually become False, otherwise, the loop will run indefinitely, causing an infinite loop.

Printing Even Numbers from 1 to 10

To print the even numbers from 1 to 10 in Python, we can use a while loop with an additional condition to check if the current number is even.

Here's the code:

num = 1
while num <= 10:
    if num % 2 == 0:
        print(num)
    num += 1

Let's break down the code:

1. We initialize the num variable to 1.
2. The while loop continues as long as num is less than or equal to 10.
3. Inside the loop, we check if the current value of num is even by using the modulo operator %. If the remainder of num divided by 2 is 0, then the number is even.
4. If the number is even, we print it.
5. Finally, we increment the num variable by 1 to move to the next number.

This loop will output the following even numbers:

2
4
6
8
10

By using the while loop and the if statement to check for even numbers, we can easily print the even numbers from 1 to 10 in Python.

Putting it All Together

In this tutorial, we have learned about while loops in Python and how to use them to print even numbers from 1 to 10.

Let's recap the key points:

Understanding while Loops

• while loops are used to repeatedly execute a block of code as long as a given condition is true.
• The basic syntax is:

  while condition:
      ## code block

• The condition is evaluated before each iteration of the loop.
• while loops are useful when you don't know in advance how many times the loop needs to run.

Printing Even Numbers from 1 to 10

To print the even numbers from 1 to 10, we can use a while loop with an additional if statement to check if the current number is even:

num = 1
while num <= 10:
    if num % 2 == 0:
        print(num)
    num += 1

This code will output the following even numbers:

2
4
6
8
10

By combining the while loop and the if statement to check for even numbers, we can easily achieve the desired result.

Remember, it's important to ensure that the condition in a while loop will eventually become False to avoid an infinite loop.

I hope this tutorial has helped you understand how to use while loops in Python to print even numbers. If you have any further questions, feel free to ask!

Summary

In this Python tutorial, you have learned how to write a while loop that prints even numbers from 1 to 10. By understanding the basics of while loops and applying them to a practical example, you can now confidently use this control structure in your own Python projects. Remember, mastering the fundamentals of Python programming, such as while loops, is essential for building more complex applications and solving a wide range of problems.