What is a loop in coding

What your kid makes

Your kid ends with a robot program that uses a loop: a 3-line Repeat in place of 8 lines, with each step placed inside or after the loop on purpose. On paper they keep a clapping program and a dance program, both written the long way and the short way.

The 4 lessons

1. 

   Lesson 1. The long way

   Writing the same steps over and over is slow and easy to get mixed up, so coders use a loop.

   1. Write the steps to clap five times, one line per clap
   2. Count how many lines it takes

   Where: Paper

   Watch it free above

2. Lesson 2. Repeat it

   A loop says: do these steps again, this many times. Change one number to change the count.

   1. Write the clapping program again with a loop
   2. Count the lines now and compare

   Where: Paper

   In the app

3. Lesson 3. Inside or after?

   A step inside the loop runs every time. A step after the loop runs once, at the end.

   1. Draw a dance program: repeat 4 times, step and turn
   2. Add one bow after the loop
   3. Dance it and check the bow comes once

   Where: Paper

   In the app

4. Lesson 4. Loops in your robot

   In the Robotics Studio, the Loops jobs open after job 3, and the shortest program earns three stars.

   1. Finish job 3 to open the Loops jobs
   2. Do job 4 with Repeat in 3 lines
   3. Try job 5, which needs more toys than Repeat counts to

   Where: Robotics Studio

   In the app

Lesson 1 transcript: The long way

1. 0:00

   Here's a job for our House robot. Put four toys in the box.

2. 0:07

   So we tell it. Grab a toy. Put in the box. Grab a toy. Put in the box. Again. And again.

3. 0:17

   Phew! That's eight tiles, and they all say the same thing.

4. 0:24

   Robots love clear steps. But writing the same steps over and over? That's slow, and it's easy to make a mistake.

5. 0:34

   Coders have a trick for this. It's called a loop.

6. 0:40

   On paper, write the steps to clap five times. Count how many lines it takes.