A Loop Inside a Loop
Loops within loops.
A Loop Inside a Loop is a free Coding for Kids lesson on CoddyKit. This is lesson 1 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Coding for Kids learning path, and your progress syncs across the web and the CoddyKit app. The Coding for Kids course includes 4 lessons in total.
Loops Are Awesome! 🔁
Hi superstar! 🌟 You already know a loop repeats things. Today we learn something SUPER cool: a loop inside another loop!
It's like a robot doing a little dance over and over, while a bigger robot makes it dance again and again! 🤖
for i in range(3):
print('Outer loop! 🤖')What Is Nesting? 🪺
When you put one loop inside another, we call it a nested loop. Just like a tiny bird's nest sitting inside a big tree! 🪺🌳
The inside loop finishes ALL its turns before the outside loop moves on.
for big in range(2):
for small in range(2):
print('hello!')Counting With Two Loops 🔢
Let's watch the numbers! The outer loop picks a number, then the inner loop runs all the way through before going back up.
- Outer = the big steps
- Inner = the little steps
for a in range(2):
for b in range(3):
print('a =', a, 'b =', b)Indenting Matters! ➡️
In Python, the spaces in front of code tell it where it belongs. The inner loop's code is pushed in even MORE! ➡️➡️
Think of it like stairs going down. Each loop is one more step in!
for x in range(2):
print('Step in once')
for y in range(2):
print(' Step in twice!')Stars and Stars ⭐
Let's make rows of stars! The outer loop makes a new row, and the inner loop prints stars on that row. ⭐⭐⭐
We use end='' so stars stay on the same line!
for row in range(3):
for star in range(4):
print('*', end='')
print()Robot Dance Party 🕺
Imagine 3 robots. Each robot spins around 2 times. How many spins is that all together? Let's let the computer count for us!
for robot in range(3):
print('Robot', robot + 1, 'is dancing!')
for spin in range(2):
print(' spin!')Inner Finishes First 🏁
Here's the secret rule: the inner loop runs completely for every single turn of the outer loop. 🏁
So if outer runs 2 times and inner runs 3 times, that's 2 × 3 = 6 total prints!
count = 0
for a in range(2):
for b in range(3):
count = count + 1
print('Total runs:', count)Naming Your Loops 🏷️
You can name your loop helpers anything! People often use i and j as short names. ✏️
But row and col are even friendlier names. Pick whatever helps you understand! 😊
for i in range(2):
for j in range(2):
print('i and j:', i, j)Make a Box 📦
With two loops we can draw a little box of hashes! The outer loop is the number of rows, the inner loop fills each row. 📦
for row in range(3):
for col in range(5):
print('#', end='')
print()Loops Inside Loops Inside... 🌀
You can even put a loop inside a loop inside a loop! But let's keep it to two for now. Three is super dizzy! 🌀
Most cool patterns only need TWO loops. Nice and simple!
for a in range(2):
for b in range(2):
print('Pair:', a, b)Your Turn to Imagine ✨
Try changing the numbers in range() and see what happens! Bigger numbers = more rows and more stars. ✨
Playing and changing things is how the best coders learn! 🚀
for row in range(4):
for star in range(6):
print('+', end='')
print()Quick Check! 🧠
Time for a fun question! Think about how nested loops count. 🤔
You Did It! 🎉
Wow, you learned nested loops! 🎉
- A loop inside a loop is called nested 🪺
- The inner loop finishes before the outer moves on 🏁
- Indenting (spaces) tells loops where they belong ➡️
- Multiply the turns to count total runs 🔢
Next up: drawing cool grids! 🟦
for row in range(2):
for col in range(3):
print('🌟', end='')
print()
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Frequently Asked Questions
Is the “A Loop Inside a Loop” lesson free?
Yes — the full text of “A Loop Inside a Loop” is free to read here on the web. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Coding for Kids course, upgrade to CoddyKit PRO. The Coding for Kids course includes 4 lessons in total.
What will I learn in “A Loop Inside a Loop”?
Loops within loops. You practise Coding for Kids with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Coding for Kids?
No prior experience is required. Coding for Kids on CoddyKit is structured for beginners through advanced learners, so you can start here or from the beginning and move at your own pace. This is lesson 1 of 4.
How long does the “A Loop Inside a Loop” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Coding for Kids lesson?
Yes. Every Coding for Kids lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- A Loop Inside a Loop
- Drawing a Grid
- Star Triangles
- Multiplication Table