Today, we are focusing on a crucial control block in ScratchJr: the Stop block. While the Repeat Forever block is fantastic for creating continuous motion, the Stop block gives you the precise control needed to pause or stop a specific script without resetting the entire project.

Our project today will demonstrate a continuous loop: Kitten running across the road to get a basketball. This teaches children how to manage an infinite loop and manually stop the character’s movement.

Setting Up the Continuous Loop

For a continuous, looping action, we need a setting that allows for repeated movement.

1. Change the Background: Select the suburbs background, which features a road. [00:22]
2. Add the Target: Add the Basketball character to the project. [00:33]
3. Position Characters: Place the basketball on the far side of the road at the bottom of the screen. Kitten should be positioned near the top of the screen, ready to run. [00:46]

We will only be coding the Kitten icon.

Coding Kitten: The Infinite Runner

Kitten’s script will be set up to move down and then immediately jump back to the top of the screen, creating a continuous running loop.

1. Start Block: Begin with the Green Flag trigger block (yellow category). [00:57]
2. Movement: Go to the blue Motion category and add the Move Down block. [01:05]
   • Note: Since Kitten will wrap around the screen in a loop, you do not need to set a specific number for the steps here.
3. The Loop: Go to the red Control category and add the Repeat Forever block to the end of the script. [01:12]

When you run this code, Kitten will move down, vanish off the bottom of the screen, and instantly reappear at the top, creating a continuous loop that runs forever. [01:35]

Using the Stop Block

Now, here is how you control that infinite loop using the Stop block.

1. Place the Stop Block: Go to the orange Control category and select the Stop block (the red square). Place it on the coding canvas next to Kitten’s main script. It is not attached to the script itself. [01:16]
2. Running the Code: Press the Green Flag to start the infinite loop.
3. Stopping the Code: While the program is running (in the small-screen view), simply tap the Stop block on the canvas. This will immediately stop Kitten’s repeating movement! [01:42]

It is important to note that the Stop block only works when the coding canvas is visible. It cannot be pressed when the animation is in full-screen mode. [01:49]

Mastering the Stop block is an important skill in our coding tutorials for teaching children how to control continuous code sequences. For structured activities, explore our collection of ready-made lessons. Happy coding!