In this article, I will explain Block Commands in Scratch 3.0. Basically, the block commands in Scratch represent the coding blocks. In fact, we have nine different categories of block commands. The following list shows these nine block commands.
- My Blocks
The following section describes each set of block commands in brief.
In order to control the motion of a sprite we can use the Motion blocks. For instance, we can move, turn, or glide a sprite. Further we can make the sprite go to a random position or even make it to bounce. Also, the Motion blocks are applicable on sprites only.
As an illustration look at the following simple script. At first, we have used an Event Block Command indicating the the script will start when user clicks on the green flag. Further, the enclosing blocks will be executing forever. The sprite first moves to 10 steps. Then, it will move to a rnadom position. Finally, it will glide for three seconds to reach at a random position. The following figure illustrates it.
In order to view the project click here.
For the purpose of controlling the appearance of a sprite we can use the Looks category of Block commands. For instance, we can switch the costume or size of the sprite or switch the backdrop or color. Further, we can use the Looks block commands to display a text. Even it is possible to show or hide the sprite and change its relative position.
As can be seen, the Sound category of block commands is used to play sound, start the sound and also stop it. Further, we can change the pitch and volume also.
In fact the Even block commands allow some action to take place when an event occurs. For instance, you can start the script when the green flag is clicked. Also, these commands are used to execute another block command when user clicks mouse or presses a key.
These command are used to execute a set of commands repetitively or when a certain condition is satisfied.
Whenever, it is required to do some task when a sensing action occurs such as touching a color, the Sensing block commands are used.
In order to perform certain arithmetic, relational, or any other operation, the Operators category of block commands are used.
For the purpose of creating variables or changing the value of variable, the Variables category of block commands are used. Also, we can show or hide a variable.
Even it is possible to create your own blocks. So, the My Blocks category enable you to create your own blocks that you can use in your project.